I don't think I've seen AVG popup like that when I'm browsing. I don't generally get cookie notifications. The thing is, this cookie is blocking my e-mail. I have an e-mail account that won't download at all because the cookie is blocking it.

I don't really want to drop all my cookies when I close my browser. I suspect this one wouldn't drop anyway since I've looked for it to manually delete and can't find it because it's invisible to me. I work all day on the Internet and use FF to remember my passwords. It would be a small inconvenience to input them all again when I need to and might be worth it if I thought FF would delete this cookie upon exiting, but I don't think it would.