Hi Andrew,
It's not your imagination, the multiple thumbnail thing is a bug in 5.7. Good news is, it's fixed in 6.0.

Unfortunately, it's been so long I kinda forget the exact fix. (Was a couple months ago.) And you're right, 6.0 is totally different from 5.7. Templates, style sheet, everything.
I *think* the title problem was also a 5.7 bug that I fixed. I'm not sure how long it's been since you downloaded album.pl, but certain "versions" of 5.7 had more bug fixes than others. I remember a nasty one where photo uploading would bugger the descriptions.txt file, and that sounds like the one you're seeing...
I guess the question to ask is, is it worth upgrading to 6.0? It's quite stable at the moment, and there are no known bugs with it. (A first!) I'm planning on putting out 6.0 final on Sunday, assuming there are no other issues found.
Here's the 6.0 feature/bug list:
http://perl.cdnarmy.ca/cgi-bin/yabb/YaBB.cgi?board=announce;action=display;num=1037723199If you decide to stick with 5.7, I can probably track down the bug fixes in the code. Doing a diff won't help though, as there are a ton of changes...
Cheers
Edit: I can probably help if you want to go to 6.0. I'd love the extra testing before it goes final. (I can delay the date, if that helps...

)