FOR OSX USERS:

The "Pro Tools LE 8.0cs3" update is required for ARIA under OSX for PT8 users.
Any older version cause all sorts of weird GUI hangs and clicking offsets.

From the release notes:
"Fixed: Mouse Offset and General GUI Problems With Third Party Plug-ins (Item #112890)
Certain third party plug-ins (...) will not function correctly underPro Tools 8. Mouse clicks are vertically offset and parts of theplug-in GUI will not draw correctly."

FOR WINDOWS + OSX USERS : 

Make sure, if you have a multiple core machine to leaveone core out of Pro Tool's multiprocessor pool. ... Ie if you have a 4cores, leave 3 to pro tools, if you have 8, leave 7 etc. (thats inaudio settings)

Here is ascreenshot of what to do: