I have the same issue. Preview works, but scan runs for about 10 minutes and then aborts. It appears the unit (SS4000) is repeatedly trying to focus but does not do so satisfactorily and keeps repeating the focus process.
I am running WinXP and connecting via a SCSI. Version 7.1.25 works okay, but the latest version does not. Please let me know if I can help with the debugging process. Thanks. Andy Anderson