Hazel register's and notify's for me, although I can't find it's
Growl.framework, it seems to be working fine with the downloads folder
new file added rule that uses a Growl Action. If you are talking
about File/Trash actions notifications, those notifications are
disabled by default, and you can turn them back on by going to Growl
Preferences -> Applications Tab -> Hazel -> Notifications Tab, and
then select those notification types in the pop up box and click the
enabled checkbox.