MySQL error 1153 while editing forum in ACP

[Stefan118]

I was editing the discription of a forum, and when i pressed the save button i got this error.
I tried it again, and again the error.

Then i just entered a random forum in the ACP ( Forums & moderators --> Forum manager --> edit forum) and hit the save button. Again the error!

I disabled all the plugins to see if that was the issue, but i still get the error.

The error 1153 says: Got a packet bigger than 'max_allowed_packet' bytes.
I googled this, and there is a lot of info, infact... TOO much info.

What can i do about this?
Using vB 4.2.1