Yes I saw this mentioned in a ZDNet article;
They state that you can "whitelist" sites where popups are needed.
Do you have that option?
I've noticed a few popups that sneak though Firefox lately and I believe this has been confirmed. I got an e-mail with a new extention to test which is supposed to improve the effectiveness of blocking certain popups that rely on plugins. It's called "Popups Must Die". I installed it but the first problem I saw was when clicking links in CNET messages. These appear to be blocked. Links on web sites work and CNET user profile links work but not links within message text. Just thought I'd pass this site along if anyone cares to try and verify this. Link here