Yep..I get about one a week. Comes in like a page/sms so it causes my Blackberry alarm thinking I have a priority page.
I saw a reg hack for 2.2 to turn off the notification on the BES Server, and also to change the message. (see Admin guide link below page 83)
http://tinyurl.com/6fy36
Didn't see one listed for 4.0, maybe it's the same...haven't tried it.