We use Canon DR 5010 & DR 6030 scanners in our environment.  Sometimes they work great and for the longest time on Windows 7 desktops and then there are other times were we can't get them to work for nothing.  I seem to have an issue getting the scan connect engine to work, I often experience errors during the driver load and freezes.  I seem to have had better success using the TWAIN driver but it's not always guaranteed either.  For example, we have a DR 6030 installed on a Windows 7 desktop (virtual desktop) which was working fine using the TWAIN scan engine for the longest time.  I just updated the hardware for this particular desktop (zero client) and now when I open the scan window and scan a document the scan window freezes, I have to end the task in order to get out of it.  I know this setup works because I have other desktops setup this way.  What I don't understand is why it breaks and what exactly I need to do to fix it.  One of the workarounds I use is to scan use the 'Capture Perfect' utility, which is part of the Canon install, and then print the scanned documents into LaserFiche using snapshot.  Any thoughts or ideas would be greatly appreciated.