Peter Dimov wrote :

Did you rebuild the Boost.Thread library with the new SP? You probably still have a dependency on the old VC runtime in it if you didn't, whereas the application now depends on the new runtime.

Yes, I did rebuild boost after installing the new SP. I couldn't figure out how to get bjam to clean boost so I just deleted the boost_src/bin directory and re-installed. The .lib files all have new datestamps so I believe they were rebuilt correctly.