Occasionally when I try to post to wall I get the Loading… screen from Facebook and it never actually loads the Post to Wall UI.
I also, occasionally, get an Alert popup with: could not find flash element on the page w/ uiFlashId: flash_12878123483414241561
I'll run some more tests with firebug monitor up to see if I can figure out why these errors are happening. Does seem like it's not on my end though.