We are running cas/cam and client 4.9.0 with the same compliance module version.
Unfortunatly I realized early that even though it says AVG 2012 is supported you need to read closer. AVG Internet Security 2012 and AVG Antivirus 2012 are supported but for some reason AVG Free 2012 is not. I am hoping this is fixed in the next compliance module update which should be pretty soon.
I did not open a TAC case on this yet as I have had so many issues with 4.9.0 I think I already had opened up 7 bugs with it including the first one that was sev 1, basically after about 30 -40 users logged into the system the cas would hard lock up, at this point I am happy to have 4.9.1 stable.