diff --git a/src/cmd/gobuild/util.go b/src/cmd/gobuild/util.go
index be50ba1cab..ac0cd03c1a 100644
--- a/src/cmd/gobuild/util.go
+++ b/src/cmd/gobuild/util.go
@@ -171,12 +171,12 @@ func dollarString(s, l, r string) string {
 // the context in which the result will be interpreted.
 type ShellString string;
 func (s ShellString) String() string {
-	return dollarString(s, "{", "}");
+	return dollarString(string(s), "{", "}");
 }
 
 type MakeString string;
 func (s MakeString) String() string {
-	return dollarString(s, "(", ")");
+	return dollarString(string(s), "(", ")");
 }
 
 // TODO(rsc): parse.Parse should return an os.Error.
diff --git a/src/lib/go/token/token.go b/src/lib/go/token/token.go
index b031b7f61c..b71d0f03d3 100644
--- a/src/lib/go/token/token.go
+++ b/src/lib/go/token/token.go
@@ -19,7 +19,7 @@ const (
 	ILLEGAL Token = iota;
 	EOF;
 	COMMENT;
-	
+
 	// Identifiers and basic type literals
 	// (these tokens stand for classes of literals)
 	literal_beg;
@@ -237,7 +237,7 @@ func (tok Token) String() string {
 	if str, exists := tokens[tok]; exists {
 		return str;
 	}
-	return "token(" + strconv.Itoa(tok) + ")";
+	return "token(" + strconv.Itoa(int(tok)) + ")";
 }
 
 
diff --git a/src/lib/http/server.go b/src/lib/http/server.go
index 438c0d915b..9398351fe7 100644
--- a/src/lib/http/server.go
+++ b/src/lib/http/server.go
@@ -329,7 +329,7 @@ func Redirect(c *Conn, url string) {
 // Redirect to a fixed URL
 type redirectHandler string
 func (url redirectHandler) ServeHTTP(c *Conn, req *Request) {
-	Redirect(c, url);
+	Redirect(c, string(url));
 }
 
 // RedirectHandler returns a request handler that redirects
diff --git a/src/lib/os/error.go b/src/lib/os/error.go
index 3861f0167e..d196abfc6e 100644
--- a/src/lib/os/error.go
+++ b/src/lib/os/error.go
@@ -15,7 +15,7 @@ type Error interface {
 // Error.
 type ErrorString string
 func (e ErrorString) String() string {
-	return e
+	return string(e)
 }
 
 // NewError converts s to an ErrorString, which satisfies the Error interface.
@@ -27,7 +27,7 @@ func NewError(s string) Error {
 // wrappers to convert the error number into an Error.
 type Errno int64
 func (e Errno) String() string {
-	return syscall.Errstr(e)
+	return syscall.Errstr(int64(e))
 }
 
 // ErrnoToError converts errno to an Error (underneath, an Errno).
diff --git a/src/lib/template/template.go b/src/lib/template/template.go
index 182a85b426..f266e6014d 100644
--- a/src/lib/template/template.go
+++ b/src/lib/template/template.go
@@ -181,7 +181,7 @@ func New(fmap FormatterMap) *Template {
 
 // Generic error handler, called only from execError or parseError.
 func error(errors chan os.Error, line int, err string, args ...) {
-	errors <- ParseError{fmt.Sprintf("line %d: %s", line, fmt.Sprintf(err, args))};
+	errors <- ParseError{os.ErrorString(fmt.Sprintf("line %d: %s", line, fmt.Sprintf(err, args)))};
 	runtime.Goexit();
 }
 
@@ -756,7 +756,7 @@ func validDelim(d []byte) bool {
 // the error.
 func (t *Template) Parse(s string) os.Error {
 	if !validDelim(t.ldelim) || !validDelim(t.rdelim) {
-		return ParseError{fmt.Sprintf("bad delimiter strings %q %q", t.ldelim, t.rdelim)}
+		return ParseError{os.ErrorString(fmt.Sprintf("bad delimiter strings %q %q", t.ldelim, t.rdelim))}
 	}
 	t.buf = io.StringBytes(s);
 	t.p = 0;
diff --git a/src/lib/time/zoneinfo.go b/src/lib/time/zoneinfo.go
index 2702285c01..751afc9314 100644
--- a/src/lib/time/zoneinfo.go
+++ b/src/lib/time/zoneinfo.go
@@ -236,7 +236,7 @@ func readinfofile(name string) ([]zonetime, os.Error) {
 
 Error:
 	if tzerr, ok := err.(TimeZoneError); ok {
-		tzerr.ErrorString += ": " + name
+		tzerr.ErrorString = os.ErrorString(tzerr.String() + ": " + name)
 	}
 	return nil, err
 }
diff --git a/test/convert.go b/test/convert.go
index 4952e01b76..1b933f93bf 100644
--- a/test/convert.go
+++ b/test/convert.go
@@ -40,14 +40,11 @@ func main() {
 		panicln("type of f is", t, "want", want);
 	}
 
-	want = typeof(x);
+	want = typeof(a);
 	if t := typeof(+a); t != want {
 		panicln("type of +a is", t, "want", want);
 	}
 	if t := typeof(a+0); t != want {
 		panicln("type of a+0 is", t, "want", want);
 	}
-	if t := typeof(a+b); t != want {
-		panicln("type of a+b is", t, "want", want);
-	}
 }
diff --git a/test/golden.out b/test/golden.out
index 92c2f8a43c..d201fb9fbe 100644
--- a/test/golden.out
+++ b/test/golden.out
@@ -146,7 +146,6 @@ fixedbugs/bug049.go:6: illegal types for operand: EQ
 
 =========== fixedbugs/bug050.go
 fixedbugs/bug050.go:3: package statement must be first
-sys.6:1 fixedbugs/bug050.go:3: syntax error near package
 
 =========== fixedbugs/bug051.go
 fixedbugs/bug051.go:10: expression must be a constant
diff --git a/test/import.go b/test/import.go
new file mode 100644
index 0000000000..9bed8213cc
--- /dev/null
+++ b/test/import.go
@@ -0,0 +1,25 @@
+// $G $D/$F.go
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// check that when import gives multiple names
+// to a type, they're still all the same type
+
+package main
+
+import _os_ "os"
+import "os"
+import . "os"
+
+func f(e os.Error)
+
+func main() {
+	var _e_ _os_.Error;
+	var dot Error;
+
+	f(_e_);
+	f(dot);
+}
+
diff --git a/test/interface10.go b/test/interface10.go
index f84da58ed1..c52a20fcd8 100644
--- a/test/interface10.go
+++ b/test/interface10.go
@@ -13,7 +13,7 @@ const Value = 1e12
 type Inter interface { M() int64 }
 
 type T int64
-func (t T) M() int64 { return t }
+func (t T) M() int64 { return int64(t) }
 var t = T(Value)
 var pt = &t
 var ti Inter = t
diff --git a/usr/gri/pretty/format.go b/usr/gri/pretty/format.go
index 7267341913..895cec276c 100644
--- a/usr/gri/pretty/format.go
+++ b/usr/gri/pretty/format.go
@@ -301,7 +301,7 @@ func (p *parser) parseValue() []byte {
 	if err != nil {
 		panic("scanner error?");
 	}
-	
+
 	p.next();
 	return io.StringBytes(s);
 }
@@ -332,7 +332,7 @@ func (p *parser) parseField() expr {
 		p.next();
 		tname = p.parseName();
 	}
-	
+
 	return &field{fname, tname};
 }
 
@@ -417,13 +417,13 @@ func (p *parser) parseProd() (string, expr) {
 	name := p.parseName();
 	p.expect(token.ASSIGN);
 	x := p.parseExpr();
-	return name, x; 
+	return name, x;
 }
 
 
 func (p *parser) parseFormat() Format {
 	format := make(Format);
-	
+
 	for p.tok != token.EOF {
 		pos := p.pos;
 		name, x := p.parseProd();
@@ -442,7 +442,7 @@ func (p *parser) parseFormat() Format {
 		}
 	}
 	p.expect(token.EOF);
-	
+
 	return format;
 }
 
@@ -450,7 +450,7 @@ func (p *parser) parseFormat() Format {
 type formatError string
 
 func (p formatError) String() string {
-	return p;
+	return string(p);
 }
 
 
@@ -517,7 +517,7 @@ func Parse(src interface{}, fmap FormatterMap) (f Format, err os.Error) {
 	if p.errors.Len() > 0 {
 		return nil, formatError(string(p.errors.Data()));
 	}
-	
+
 	return f, nil;
 }
 
@@ -593,7 +593,7 @@ func typename(value reflect.Value) string {
 	case reflect.Uint8Kind: name = "uint8";
 	case reflect.UintptrKind: name = "uintptr";
 	}
-	
+
 	return name;
 }
 
@@ -616,11 +616,11 @@ func (f Format) getFormat(name string, value reflect.Value) expr {
 		panic();
 	}
 	*/
-	
+
 	if fexpr, found := f[name]; found {
 		return fexpr;
 	}
-	
+
 	if *debug {
 		fmt.Printf("no production for type: %s\n", name);
 	}
@@ -695,7 +695,7 @@ func append(dst, src []byte) []byte {
 
 type state struct {
 	f Format;
-	
+
 	// indentation
 	indent_text []byte;
 	indent_widths []int;
@@ -868,7 +868,7 @@ func (ps *state) print0(w io.Writer, fexpr expr, value reflect.Value, index, lev
 			w.Write(buf.Data());
 		}
 		return true;
-		
+
 	case *option:
 		// print the contents of the option if it contains a non-empty field
 		var buf io.ByteBuffer;
@@ -888,7 +888,7 @@ func (ps *state) print0(w io.Writer, fexpr expr, value reflect.Value, index, lev
 			buf.Reset();
 		}
 		return true;
-		
+
 	case *custom:
 		var buf io.ByteBuffer;
 		if t.form(&buf, value.Interface(), t.name) {