I installed the latest beta (using the cleaning tools provided in the thread as well), in an attempt to prevent this issue, yet it's a sure thing that after my computer has been running for an extended time, the AvastSvc process will lock itself at 25%, 50%, 75%, or 95% of my total CPU.
I just got it back down from using 95% and almost completely freezing my computer by turning off the active shields for a while, with the web shield freezing the avast UI process for nearly ten minutes when I turned it off.
During these times, I can look at the statistics page and literally nothing is happening. No sites or files are being scanned, yet the avast process continues to use up to 95% of a 4.2ghz quad core processor.
Attached image was taken something like a day or two ago, because this time it had my computer so locked up I couldn't take a screenshot.