...an expired McAfee AV...
Scythe944?

Bishop,
This could probably be the reason.
Is it still installed? I presume you don't want it anymore...
Download the McAfee removal tool,
http://download.mcafee.com/products/licensed/cust_support_patches/MCPR.exeUninstall McAfee from add/remove in the control panel
Run the removal tool
Repair avast! through the add/remove...
I think that should do it
-Scott-