This happend to me on a couple VBB sites and i thought it was because i had logged onto the site using a customised user agent. (This 1 site crashes my browser WHEN I LOGIN unless i do,i dont know why)
I forgot to remove it a couple times when i logged onto two other sites (Which it happend right after that on both of them)
1 of them WAS A VISITOR MESSAGE in the moderation Queue (I COULDNT SEE IT,I DUNNO WHY) but i dont know what happend @ the other site to cause it....... (Its strange it happend ON BOTH SITES right after logging on with the added stuff in my user agent.. (I thought MAYBE it messed up the sync with the site or something)) Maybe it didnt i dont know.......
Im glad i saw this thread!