I don't really see a forum for this -- first post -- I guess I'll just ask here.
Very frustrating problem because it would seem that it would be common (it's happened to me on a couple of devices) and that there would be some specific answers.
One area that was brought up is USB power management but been there, done that.
I have an ATI USB TV tuner that will uninstall when I shut down the PC (BOTH of my PC's -- XP and Win7).
When I power down, I have to disconnect it -- then power up -- wait for a complete reboot and plug it back in for it to operate and show up in device manager. (tried ATI's theatre driver, let windows 7 search etc etc)
I've tried to solve this for the past several months and no luck with google searches, other posts, even "trying" to contact Diamond MM -- so thought I'd try here.