Problems every month or so with encryption/decryption
 

Hi Guys
It seems that every month or so, we suddenly have a batch of users whose Blackberries fail to work. We are getting the error Encryption/Decryption error and the device can't send or receive. The weird thing is, when it happens, a block of users are affected which makes me think this is a server issue.
What I am doing now is to reactivate them via Enterprise Activation to get them up and running again.
Anyone seen this problem?