We had a customer yesterday that had their Blackberry server suddenly stop sending mail. I remoted into the server and found that they had an SRP identifier connection error.
The key started with a T instead of an S. That told me that they were using a temporary key and it just expired on them.
They had the key that started with an S but even after I installed it there was a connection error.
The issue with this is that you have to call RIM for support, and if you don't have a contract you either have to pay for the ticket or explain to them they just need to activate a key that they already sent you.
Fortunately I had a contract so it was not as big of a problem but it still took several hours before I could get them to figure out how to activate their own key.
Well, at least we get paid by the hour, and it wasn't our mistake.