We have had two 8310 devices for a specific user, and have had the same problem with both. Basically, the Curve keeps turning off it's own Radio Frequency. The user has to go to wireless connections, and re-enable it. The device then reconnects to the wireless network.
I have tried a device swap, two Curves and they both do it!
There is a discussion regarding devices doing this on the 8700 forums, but I wondered whether any 83xx users had more info or a more specific fix: http://www.blackberryforums.com/gene...turns-off.html
There is one interesting post, which I wondered whether you had any thoughts on:
"from what i have been told the error i posted is a carrier issue. the device is not registering with the carrier (or there is a previous registration still present) and so it disconnects. While mine is connected for that 20 seconds, it will send/receive email, PIN, SMS, and Phone calls with 0 issues. at that 20 second mark, even in the midst of transmitting, it errors out"
I have contacted the network and asked about this, and am still waiting for a response...