I have been told by many people that you cannot run two virus scanners on the same machine. I understand if they were running at the same time they could conflict.
AdAware 10.5 says in its manual that it is designed to be compatible with other AVs. If installed in compatible mode it will install no drivers and have no real time protection, only the scheduled scan.
I use AVG Internet Security 2014 and have AdAware in compatible mode. Is the prohibition on two virus scanners in effect here? If so, it would mean AdAware is misrepresenting their program or people are using outdated information.