I've actually had better threads success w/ 5.8.6 on Win32 (XP to be precise); 5.8.7 occasionally throws some odd errors out of threads::shared. At least, thats been the case while testing DBIx::Threaded, Thread::Queue::Duplex, and Thread::Apartment.

As an independent test of a similar environment, you might want to try installing DBIx::Threaded and testing with DBD::SQLite, as it has many of the same issues as Perl/Tk (ie, lots of XS code, not threadsafe, but can be run inside its own thread). If it coughs, it might be a problem with your configuration or WinME (I've never used the latter w/ Perl threads, only WinXP or 2K).