Devices Upgraded to 5.0.0.591 need BES reactivation

[bbwitch]

I've been browsing thru the threads here hoping to stumble across this issue we're facing and haven't found it yet.

We're running BES 4.1.6.20 with Groupwise (yeah, I know - not many of us around anymore)....

One of our non-IT people recommended that all our BB Tour users upgrade to version 5.0.0.591 for the PTT capability of the device. Users are doing this upgrade on their own (which is taking a minimum of 2 hours to do wirelessly) and find no immediate problem. After a few days, though, we're seeing that some of these upgraded users are disconnecting from the BES (they stop receiving email) and the only fix is to remove them and add them back to the BES before performing an activation. Of course, this is where they're running to IT people for help.

This isn't happening to all of them, but scattered users here and there, and they all have the upgraded version in common.

A call to RIM was met with the "best practice is to reactivate the device after an upgrade" but that was it. Has anyone seen anything similar?

Thanks!