A number of users have experienced an issue in which various USB devices do not work properly or at all after systems that have been upgraded to Windows Vista SP2 wake up from sleep or hibernation. In some cases, USB devices do not respond for 30 seconds or more after the system has awoken; in other cases, functionality is missing or the devices do not respond at all.
While many users still experience these issues after applying this fix, Microsoft has released a downloadable hotfix that may resolve the problem in some cases.
You may also want to try deleting the INFCACHE file then restarting. Instructions for this process are as follows: