Yes, I have heard bad things about the video and image. Shame the vids don't give out a higher pay..as they look some of the most intriguing of all ads!
Have you thought about showing Revver Videos instead of Youtube? Revver is the same as youtube only they show an ad when the video finishes, if your user clicks on the ad you get 20% of what the advertise paid for it. Can make some alright money (better than adsense) if you use video sites