Hey sean,

AVG is a known problem with DNN 5 and many web hosting environments - oh and dont even bother thinking about installing it on non-linear video edit suite system. DNN 5 accesses many elements dynamically thru its httpmodule providers and caching providers and AVG sits in the middle trying to intercept every single request to access any of the files these providers are trying to request. 

When you consider that in a single page request cycle potentially hundreds if not thousands of files are being accessed in quick succession - and then you put avg over the top intercepting each file request - and trying to check that file for viruses - OUCH.

This is especially the case when you are first starting the application pool - as the compile process is writing a large number of new files to temporary storage - and of course avg is again getting in the middle trying to examine each file BEFORE it gets written to the drive.

I don't have any issues with virus checkers as a rule but avg is not a good option for any server based environment as the way it functions is detrimental to server performance on so many levels.

Westa