So, stopping the service doesn't help wither... hmm... very odd, I have to say.
I'm just wondering what is left running on the system once you turn the service off.
It's basically just the avast kernel drivers, but these should be more or less switched to "pass-through" mode as well.
What we could try is prevent the new drivers from loading, and see if it makes any difference.
Could you guys please try one more thing?
1. with avast 4.8 installed, boot into Windows Safe Mode
2. from there, run regedit and navigate to HKLM\System\CurrentControlSet\Services
3. in the aswSP and aswFsBlk subkeys, change the value called "Start" to 3 (manual start).
4. reboot the system
This will suppress the avast self defense drivers. I'll like to here if that solves the problem (with the service either on or off - but it shouldn't be too relevant).
Thanks
Vlk