bumpski - 4:43 pm on Jan 14, 2011 (gmt 0)
Have you done the supplemental test?
If your pages have gone supplemental the images from those pages will not be indexed by Google Images.
Hopefully this is one step toward researching your problem. Of course it would have been very useful to know the results of this test before your problem began, but at least it can be helpful in researching the problem.