Re: visual studio 2005 C++ link error

I'm porting a project from 2003 to 2005 and now I get a linking error.
I have a library called ts_exception.lib which using std::strings and
when linking in that library I get the following error message:

msvcprt.lib(MSVCP80.dll) : error LNK2005: "class
std::basic_string<char,struct std::char_traits<char>,class
std::allocator<char> > __cdecl std::operator+<char,struct
std::char_traits<char>,class std::allocator<char> >(char const *,class
std::basic_string<char,struct std::char_traits<char>,class
std::allocator<char> > const &)"
(??$?HDU?$char_traits@D@std@@V?$allocator@D@1@@std@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@0@PBDABV10@@Z)
already defined in ts_exception.lib(iexception.obj)

It seems the compiler has instantiaited "operator+(char*,string &)" in
both modules and is confused on which one to pick. Is this a known
bug? Should I upgrade to SP1? thanks for any help.