Attachment page links keep breaking

Devin, thank you for the beautiful site. Everything is going well except some recurring issues with the attachment slide-show pages at the end of the portfolios. Some images appear in slide-show format but more than half are giving the “This is somewhat embarrassing..” page. We are updating captions and that sometimes triggers the broken link, other times it happens immediately after uploading. Re-uploading the images seems to fix it, at least temporarily, but I’d like to figure out what I’m doing wrong.

A portfolio: http://trishandjill.com/?portfolio_category=installation
and click on, for example, the elephant “Child’s Room”. Only about 3-4 images will appear in the slideshow, the rest will give the error message when clicked. The permalinks and ids all look correct to me. I’ve regenerated thumbnails and re-saved the permalink settings. I’d appreciate any advice.