With Ubuntu 9.04 the behavior of the notifications for software updates has been changed a bit:
software updates do not get anymore highlighted in the notification area, but the update-manager simply start minimized and hardly catches my eye …
Reverting back the behavior to the sane old one is very simple …
There’s a gconf configuration option that can be used to disable the new behavior:
or you can simply run the following from the command line:
gconftool -s --type bool /apps/update-notifier/auto_launch false