I got my Droid 2 Global in June 2011 thru Verizon. I live in the country and according to their coverage map, my house is in their extended 3G area. (3G is about 5 miles east.) My plan covers roaming, so I just keep the data roaming option checked.
Last week of October, I got my first system update. Ever since then, this option keeps unchecking itself- seems like hourly. I get notified if I am trying to do something that my roaming is turned off and I can turn it back on, but this is getting to be a pain!
I called Verizion and they suggested sending me a new phone. Personally, I really don't want a new phone and have to reset everything up again. (I finally did a factory reset so that I could access the Market App that got all screwed up by a deleted gmail address.) Since I didn't have the problem prior to the upgrade, I am not certain a new phone would fix it.