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

2 Comments
hi, i found this, probably happens all the time, or maybe I just had luck. When i put the getURL code for an onRelease event, the popup blocker stoped it from opening. However, when I put the getURL code in a onPress event, the popup window would open with no problems at all.
I think it’s the opposite. It works with onRelease but the popup is blocked if you use onPress event.