Conflict between Avast 5.0 and Wacom drivers

I recently set up a new Windows 7 64-bit system. I installed Avast 5.0.545.0 on it. About midway through setting it up I noticed that Avast had stopped working. Similar to this thread, all avast shields and services stopped working, and could not be re-enabled. I reinstalled Avast and rebooted, and it worked again.
The computer this was happening on uses a Wacom tablet for its mouse. The mouse starting having problems, and soon after stopped working.
I reinstalled the Wacom drivers. The mouse works now, but Avast is broken again.

For now I need the Wacom working more than I need Avast, so that is the state it’s in.

I contacted Wacom support, and their response was what I had surmised:

Unfortunately some anti-virus programs do not allow the tablet drivers to function properly. This is not a common occurrence but it can happen with specific programs. At this time your options would be limited to using one or the other, or trying a different anti-virus program.

That’s a little disappointing.

In the same thread that I referenced earlier there was a response from Avast support saying that there is a problem with Avast and restore points, soon to be fixed.
Does that apply to my scenario? Because it’s not just installing the drivers (probably creating a restore point in the process) that breaks Avast, but also that reinstalling Avast conversely breaks the Wacom drivers.

I had tried two different versions of the driver from Wacom (for a Graphire4 tablet):
New Driver 5.2.1-6a for Windows 7, Vista & XP (32 & 64 bit versions) (Mar. 15, 2010)
Driver 5.2.1-6 for Windows 7, Vista & XP (32 & 64 bit versions) (Nov. 25, 2009)

Thank you for you time and any input you may have!

Staple, how many folders do you have in “\Program Files\Alwil Software\avast5\defs” ?
Thanks.

One. I reinstalled it again today to troubleshoot some more. It looks like a dated update folder: “10060702”