I have version 22 and have only really had the problem recently. Besides, I noticed that during the defragment part of tune up, it was trying to defrag its own backup files on the external USB drive. It seemed to finish this task reasonably quickly and move on to the virus scan. However although I could find nothing with task manager, the resource monitor on Vista was showing DfrgNtfs.exe running at 56%. This and the scanner were hogging up the system. So I rebooted, turned off the external drive and tried again. This time there was no problem. I suspect that when I turn it on again the problems will start again.