ultrafop, did you manage to solve this issue?
I'm observing it right now, after the latest update to r244, in the project that didn't have such problems with previous versions of Construct 2. I've been checking on two machines with integrated Intel video card.
I wish, buddy. I thought it was specific to Nvidia but it seems you're having the issue with intel... Maybe it will be addressed if it starts impacting more users?
EDIT: If you turn off effects preview in the editor, you won't see your effects, but the distortion will go away.