Just a recap to see if I understand the situation here. You're using SE to build a VS .sln, and the symbols aren't being built correctly when doing so?
Assuming the answer to the above is yes: Can you invoke the VS build directly from a command line devenv MySolution.sln /Build "Debug|Any CPU"
and produce the proper symbols? If so, remove the "|Any CPU" from the command line and try again. If you get the bogus symbols, please open a bug at the SE support site. The VS invocation in SE is a bit broken (for example, when you build a complete solution, it doesn't pass the entire config, just "Debug" or "Release", even though it needs the PlatformName in all but the most trivial cases.), and would benefit from some love by the SE team. You might have found the compelling case to get it done.