Im sorry guys but the log file does not have anything in the warning file for today. I dont know. It did say to ignore it. Im sorry I did not retain more information when it happend. After this weekend fighting all the trojans I kinda freaked out a little.
If it said to ignore it then it wasn't a standard scan, but likely to be the anti-rootkit scan that takes place 8 minutes after boot, this normally give two options Ignore and Delete and avast gives a recommended course of action. You should allow avast to send a sample for analysis (the default setting).
This heuristic style scan doesn't log entries in the warning section like normal scans, but in the C:\Program Files\Alwil Software\Avast4\DATA\log\aswAr.log file (you can view with notepad), this is overwritten on the next anti-rootkit scan.
You would have to be fast off the mark to be downloading or updating MBAM at that point though. So I don't really know if this is exactly what you saw.