With a little help from this thread, and something I read elsewhere about editing the filtered flash selection and clearing all its details but for its name, I finally managed to get a Patriot 4GB Flash drive recognized and working with W7 on a Leopard host ..and it comes up again after a restart!

The USB 'filters' setup is confusing, and not well enough explained for OSX users...
The other problem I am having difficulty with is ReadyBoost (RB), which appears not to work at all in the W7 VM, even with known OK RB drives.
I should perhaps start another thread about that, but if anyone can confirm ReadyBoost does not work at all on W7 VM, pls let me know

Mvh