this is the second user with this 'firewall' problem i have had since i changed to version 7 two days ago. any clues whats up?

Hi Marty,
All of the sudden this evening I started to get this error message (below) when attempting to post or PM someone. No firewall changes on my end.
Thanks for any insight you may be able to offer.

DB

-Quote-
"We cannot proceed.
The host from which you are accessing the board is not recognized as a valid host. This is more than likely related to a firewall issue that is blocking the referer variable. Check your firewall settings and try again."
-Unquote-