I was told to go ahead and blog about it just in case folks cannot figure it out
When I blog about things, especially what I consider bugs, I always like to include that “Microsoft is aware of the problem and investigating” before it sounds like I’m just bashing Microsoft or something, but rather just to be informant to users so that they can understand what they need to do to remedy the problem.
The scenario is when you have a domain user, and a domain group both with alerts created for them.
When you remove the user from the site collection as a whole, their alerts are completely removed (Can’t remember if we did this for V2, something tells me we didn’t)
BUT, when you remove a domain user from the site collection, and their alerts were created via a domain group, they are NOT removed.
The group still shows up in the alerts view screen, but hitting update of course reports and exception of “User not found” because the user (Domain group in this case) does not in fact exist anymore in the site collection.
Therefore, the admin has no way of actually going in and clearing up the alerts without first adding the domain group back into the site collection, then selecting and removing the alerts, then removing the domain group.
But you have to add the group back to delete the alerts. A bug will be filed for V3 SP 2 consideration