oncameratalent - 3:47 pm on Oct 30, 2010 (gmt 0)
I have always run text only ads after doing some initial testing. I too have been receiving the same message from Adsense regarding image-ads not running on more that %50 of my sites.
It very well may be a fact that the majority of publishers use text only ads, and Adsense wants to push the image ads for various reasons.
I decided to give it a try again, and will report back. So far this morning I am doing better than average for this time on a Saturday morning.