You write that you use Avast AV and CIS+AV. So you are using two AV programs at the same time witch is never a good idea. Switch off (disable) Avast and you should be fine.

, I have experienced what can happen when Avast! and CAV both have real-time scanning on....

Disable the real-time scanning in Avast! or CIS (see
this guide, by me

).