Hi,
we have a similar problem appearing non-deterministically. After several edits and saves, the saving “freezes” and the browser is just infinitely “Waiting for server…”
Once it happens, it does not help to log out and log in nor switch browser. A workaround I found is to log out and clear Active sessions (this is how it’s called in latest FF beta 3.1 which has also a nice feature that you can clear just session from last hour). Then log back in and you can save again, sometimes only once.
Thanks for any help with this annoying problem!