Security issue problem: Opera and gmail

Hello everyone!
since I upgraded to avast 8.0 I am getting popuot security issue window in Opera browser saying: The server certificate chain is incomplete, signer is not registered. Servers name: pop.gmail.com
How to get rid of this annoying popout. Thanks a lot for any help.

hey this might solve your problem.

http://my.opera.com/community/forums/topic.dml?id=1518812

Thanks Mikaelrask,
unfortunately there is not a concrete solution to my problem. I would like to point out that only server pop.gmail.com doest it.

hey agian does you get anything from opera forum if you write there?