Keep being unprovisioned on RIM data network

I would greatly appreciate it if my 1XEV would stop dropping to lowercase 1xev, which means that I am no longer on RIM's network and therefore unable to get email, web and IM on my BlackBerry Curve.

This seems to happen every two or three days, sometimes more than once in a day. It's very frustrating to have this happen, as I am given no alert that I've been removed from RIM's network until I look at my BlackBerry and see that the 1XEV has been put to lowercase.

This is a problem with the Metro PCS network, not my phone, as this problem does not happen when I'm in areas with good coverage, such as Wixom and Milford, Michigan. I sincerely hope that Metro PCS is upgrading network coverage in Southeast Michigan so this loss of data service will become a thing of the past.

Thank you.