Compile problem fixes

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_2_BRANCH@6917 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/wxexpr.cpp

@@ -754,7 +754,7 @@ void wxExpr::WriteExpr(FILE* stream)    // Write as any other subexpression
       if (quote_it)
         wxFprintf( stream ,wxT("'") );
 
-      wxFprintf( stream, val.c_str() );
+      wxFprintf( stream, (const wxChar*) val );
 
       if (quote_it)
         wxFprintf( stream, wxT("'") );