Yep...I started getting that the other day.  I noticed that everytime I tried to look at one particular topic, I would get that error.  I went down the forum list and tried every other topic in turn...no error.  I then tried to go back to that topic...error box popped back up.  I figured it was someone's signature or avatar, so I went and turned them off...turned off everything I possible could.  So far, that particular error message hasn't come back, but the other hard lock issues still remain.