I just discovered this lovely bug this morning. Basically the regular expressions do some wierdness to links that remove the href from them and cause the xmlHTTPRequest to go into an infinite loop. I have a strong idea of where the problem is and hopefully will issue a fix soon. My apologies to anyone encountering this problem.
In the meantime you have a couple of options:

• If you handcraft your links to be lightboxed make sure you have Do Not Auto-Lightbox Images checked and Auto-Lightbox Text Links unchecked.
• If you use auto-lightboxing make sure you do no handcraft links to be lightboxed.

Hopefully have this fixed soon.