Randomly generates linker errors

[cobolt_dink]

For seemingly no reason sometimes when I try and compile MSVS 2005 will throw a bunch of linker errors like: libcmt.lib(invarg.obj) : error LNK2005: __invoke_watson already defined in MSVCRT.lib(MSVCR80.dll). I can create a new project and copy the source over and it will compile fine but I make some change and then it does the errors again even if I switch it back. Only way I can get it to work is by ignoring libcmt, but it seems very strange it doesn't give the errors everytime.