CIS 4 preventing my Aspire One to sleep

I’ve noticed this few times. With avast! 5.0 Internet Security, while leaving computer alone, it turns off the screen and later on goes to sleep. However wwith CIS4 installed, it never does that.
Instead, the screen turns off, but instantly reappears again. So it’s constantly blinking when it wants to turn it off. And because of that, it never goes to sleep. Uninstalled CIS4 and installed avast! again. And screen is properly turning off and computer is going to sleep without any issues.
Can smeone look into this issue since it’s really annoying and is driving me nuts.

I’ve found with time to sleep = 3 mins or less this ds not happen!

Best wishes