This problem may be related to my earier question.
After I have scanned a couple of postcard sized photos using Arcsoft Photo studio 5.5 I get the following message:
"There is not enough free disk space to complete the scan. Scanner driver will be closed. Code: 31,0,0"
I then run CCleaner, shut all other programs and even reboot, but the problem always reappears. I neve had this trouble with my earlier version.