MBAM quick scan works ok. Full scan quits under 1 of 2 scenarios: (1) While scanning Norton Q-backup the message says MBAM has stopped working correctly & Windows will close the program. (2) While scanning Norton Q-backup error message 721 (0,28) appears. I close the message & the scan continues for about 5 minutes then the message appears that MBAM has stopped working correctly & Windows will close the program. MBAM has been deleted & reinstalled once. (Note: Ad-Aware anniversary editon has developed a problem where it freezes on a scan but the time counter continues to run. Did not used to do this. I can disengage Norton's Tamper Protection before starting Ad-Aware & the scan runs OK. Tamper Protection disengaging has no effect on the MBAM problem.) Full scans by all other security software does not find anything unusual. System: Q9300 2.50--IE-8 & Vista Home Premium SVC PK-2. Security: Norton 360 3.0/ Malwarebytes 1.40/ Threatfire 4.5.0.24/ Ad-Aware Anniversary/ SpyBot Search & Destroy 1.6.2 (Only a back up while I found a workaround for Ad-Aware.) MBAM & SpyBot were the last added & because of the Ad-Aware problem. Vista, N360, Ad-Aware & Threatfire all played nicely together until about the time of the update from N360 2.0 to 3.0 but, this could be purely coincidence. Any ideas will be helpful. (I'm not a novice but far from an expert also.) The problem is an inconvenience that should not be but not a killer. I can live with it if necessary.