I am new to the forum but have had a good look around and couldn't find a similar problem anywhere so thought it may be worth a post - apologies if it is a bit long winded
We run BES 3.6 and I have been running my 9300, 5.22 firmware without issue for a couple of months.
2 weeks ago I lent my 9300 to a client along with the Nokia desktop manager so that he could try it himself on their 3.6 BES (he was going to use his 7290 SIM in my 9300)
He used the Nokia desktop manager package to change the PIN of the device that the BES recognises from his 7290 to the 9300 and it worked fine. Once he regenerated the DES key manually he received emails for all of about 5 minutes and then the 9300 just hung.
The SIM went back into the 7290 and using the Blackberry desktop manager he reverted back to the 7290 but it seemed to hang up the BES. He could now not send any emails from the 7290 and it only reverted to normal service when they restarted the BES.
They tried with another user and got the same result. The 7290 was fine, they then put the SIm in the 9300, it worked for a bit and then hung and when they replaced the SIM to the 7290, it wouldn't work until the BES was restarted.
I have swapped around devices on our 3.6 before without any problems and the network provider had no suggestions so any pointers would be great.