Hi, could you try the following fix?

How to install it:

  1. Download the file http://www2.asw.cz/misc/aswtdi_fix.zip
  2. Unpack its contents to the following locations:
    a) \setup\inf
    b) \windows\system32\drivers
    (overwrite existing versions)
  3. Restart the machine.

Please let me know if it solves the problem.

Note: the fix only works with the latest relase version of avast
(4.5.546).

Cheers
Vlk