We're seeing lots of people with devices which stop working
after a few days, and Vista can't reinstall the drivers.

My problem is that I don't have this bug, so I can't help debug
it. But if I did have the bug, this amazing utility would be
my first choice of tools:

http://www.microsoft.com/technet/sys...ssmonitor.mspx
[Hm. Watch out for line-wrap, and the 'download' button is
way at the bottom of the page.]

I've used it on XP to solve a few mysterious problems, and
I've seen that it works on Vista -- but I don't have any
Vista bugs that need fixing (

This is not a tool for the total newbie, but if you have the
'disappearing driver' bug and, well, for example, maybe you've
at least heard the word 'regedit' before, I'd be willing to
try to walk you thru the fairly simple steps needed to get
ProcMon up and running.