I have had the same happen to me not only on the OB but other sites as well. The character count either max. or min. is set up through the programming here on the OB. It's a script in which allows a number of characters within a text area and is helpful in keeping imput length in check. Twenty-five characters include spaces as well as typed keys. Now whether or not the OB and other sites have a character count on a max is to be seen, but if one has an over abundence of being a chatter box than I would suppose it could be posted in the "publish story" ...
I would imagine if we had a max it would be posted somewhere on the message screen, which is doubtful. If I am incorrect on this one, maybe someone with a bit more technology could enlighten us all.