Don't take my word for it, but to me it seems like your MSBuild configuration got corrupted somehow. Try repairing the compiler installation (particulary VS integration part). If that doesn't help, you might want to try repairing VS2010 installation as well. I messed around Microsoft SDKs folder (tried to install 7.1 and delete 7.0a), and got similar errors -- had to reinstall both VS2010 and the compiler afterwards.
Bewilderingly, it's working without trouble now. I hadn't reinstalled Composer, but I installed several related products - VTune, TBB, IPP, InspectorXE, so perhaps they corrected a bad environment variable somewhere.
When it was still an issue, I could compile a very simple IPP sample and get the error, so I believe it was unrelated to the source.