not running MBAM. I run a lot of AVs with MBAM and no problems at all. What Avast doesn't catch MBAM typically does. Avast is very fast on the draw, but it is primarily an AV product. MBAM obviously uses different heuristic techniques to catch intruders, otherwise I would see evidence of events and errors in the Event Viewer. Not with MBAM. The last AM solution I used that was in conflict with the resident AV, was AdAware - you couldn't tell there was a conflict by running the machine, but you could see it was not good in the event viewer. Also I was testing NIS 2010 with it, and Norton had its own viewer back then that also showed a conflict with AdAware. This was ONLY because the built in AV would re-enable automatically everytime it updated. Now you can't turn off the Viper AV engine in that new Lavasoft product, so you have to go all in, if you like AdAware 10. I personally feel my other kernel based solutions are more reliable, because they don't rely on obsolete signature IDS, and they apparently conflict with AdAware and cause system instability. I don't trust the owners of Lavasoft anymore anyway, but if my clients have nothing in particular to lose - I let them use it, as it has a very good anti-malware component.

This is only the tip of the iceberg in terms of a blended defense - I could go on and on about various solutions that all use different technology in providing active, and passive real time protection, but I'd have to hijack this thread, and write a dissertation on it, and I don't think that is appropriate for this discussion.