Last modified: 2012-01-04 21:49:35 UTC
Has started happening recently
*** Bug 25543 has been marked as a duplicate of this bug. ***
The cause was found in bug 25543: no title was given to the thread.
Also happens when I'm logged out. No javascript errors.
*** Bug 25730 has been marked as a duplicate of this bug. ***
See r75961 for some very ugly bandage for the problem. It allows at least anonymous to submit replies again, don't know if it fixes all other cases too.
Haven't had this problem for a while.