I'm seeing this on a Dapper amd64 box too. For what it's worth, the workaround is to not close the pop-up window; just minimize it and continue to browse in another tab/window. Or, alternatively, find the offending tab and reload the offending page, but this can often result in yet another pop-up, so it's a bit frustrating.
I have a few pages which seem to be causing this, but the problematic box is at work -- I'll try to remember to get back on Monday. -- Page that crashes firefox https://launchpad.net/bugs/40769 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
