Hide it after an update, and less than an hour later, it'll popup again.
By design. What do you think it should do? Come back after a day or just not until the next update?
I don't think it should show back up at all. I hid it in the first place... I guess it could show again as a reminder next time some updates are made (to remind you that even though the new updates don't need a restart, the old ones did).
But reappearing all the time is a right pita.
Fixed in 9d325f19f37fc7115f07e508cc8c074a0b4903fb, thanks dude.
gnome-packagekit-2.27.3-1.fc11 has been submitted as an update for Fedora 11.
gnome-packagekit-2.27.3-1.fc11 has been pushed to the Fedora 11 stable repository. If problems still persist, please make note of it in this bug report.