I've found Firefox has one of the best popup killers around, perhaps a little too good in fact. Since the 1.5 release, getURL statements that launch a page in a new window from Flash are also blocked.

This was bound to happen when evil spammers turn to Flash as a refuge for their popup launching activities, the problem with that however is that settings manager for some of the advanced Flash Player settings is also triggered using getURL.

http://www.macromedia.com/.../settings_manager02.html

Unsuspecting users could encounter this problem when they get presented with a Privacy popup question in the Flash Player and click the advanced button.

Manish Jethani also has a more detailed post about this issue from a Flex perspective

Posted
AuthorPeter
CategoriesFlash, Flex