There have been a number of annoying little problems I've been having with the last few WebKit updates and Facebook.
1. I am unable to type in the text box of a message. Any other text box on the site (wall posts, comments) works fine, but the body field of any message is broken.
2. When uploading a photo to someone's wall, the process begins, but then hangs just before the page should reload with the newly uploaded photos. If I reload the page at this point, the photos do appear on the site as uploaded, but I shouldn't have to manually reload the page.
3. I am unable to record video directly through Facebook's flash based recorder. The Flash app simply doesn't load. And when trying to upload a video that I recorded with Photo Booth (or any other video type), the same thing happens as in problem #2, except the videos don't show up after reloading.
[Amendment] You can scratch issue #3, it seems to be working now.
It’d be a good idea to file separate bug reports about your other issues as they’re unlikely to have the same underlying cause, and it would only confuse the issue to have them both tracked in a single bug report.