Okay, I've done as you suggested, M. I've taken out the more recent post (with the photo-letters) that was made after the problem started. ;P Somehow, it's not helping, but I don't wish to delete the rest of the posts either so .. guess I'll try something else.
Oh, I also tried resizing the elephant and camel pics from the festival post, but that didn't seem to affect anything. So, I've returned the elephant and camel to their original sizes. ;)
This happened once before (or something similar to it anyway), and I removed a banner from the page; everything seemed fine after that. So I guess I'll take a look at various jpegs to see if any are the offending pic. It's funny how something will work for months just fine, then one day, bam!, it's all messed up.