Using AV pro 2012 on Windows XP. While trying to address a problem with system slowdown I followed tech support suggestion to disable and reenable Bitdefender options one at a time to try to isolate problem (separate discussion). After I did that, I found that both Thunderbird and Firefox began prompting me for security exceptions for certificates. I was required to download Bitdefender root cert and restart mail and browser, however several things still don't work because of problems with certificates. For example, one exception is for the yahoo mail server (pop.att.yahoo.com) and the certificate is issued by Bitdefender Personal CA.Net-Defender. The program I use for a password vault will not work at all.
Something I did in Bitdefender caused this change in behavior, but I'm not sure what and not sure how to undo it. Thanks for any help.