I hope that somebody here can help me. Everything has been working fine on my site until this morning. Thumbnail images were showing up correctly last night but when I went to the site this morning most of them are gone. Only the alt text is showing. The thumbnails show up when you click through to a category page and they show up fine on the post page but have disappeared from the home page.
The site is www.DiscoverRoundRock.com
One other thing that may help figure this out is that I have the Sexy Bookmarks plugin installed. The images at the post level for that have disappeared also. So it seems that it is not isolated to the thumbnail generation.
One more thing. The thumbnails that are showing up on the home page all seem to be smaller in one dimension or the other (or both) than the dimensions set for the thumbnail.