I FOUND THIS ON ANOTHER FORUM - IT HELPED ME AND WORKS NOW. Hope this helps
Hey guys, I just created an account over here to give my opinion on what might be happening.
1st, never listen to a VZW customer service rep. That is like calling my mom and asking her to change my router settings. It's confusing for them and makes you more stupid.
Below is what I posted on a thread over at droidforums.net:
"Do you have the power control widget on one of your home screens? If not, long press on a home screen, Widgets > Power Control. See if you have toggled off the data sync (it is the one 2nd from the right, looks like arrows in a circle).
If you have that toggled on, the next thing I would try is go to Settings > Data Manager > Data Delivery > Make sure background data is checked, and that data is enabled.
If you have done the first two steps, the next thing I would try is go to Settings > Accounts > click on your gmail account > make sure syncing contacts, gmail, and calendar are all checked.
Another thing to try is go to Settings > Applications > Manage apps > All > Gmail > Clear cache & Clear data. It will take a minunte or so (or longer depending on your inbox size) for the app to sync but you should be all good after that.
Thats all I got on this issue. It seems like I was having this problem sometime ago, and these steps helped resolve it.
One other thing, I use an app called Quick Settings, I think its pretty sweet. It's just like the power control widget (but its an app, not a widget) but you can also control mobile data, along with wifi, gps, bluetooth, auto syncing, and much more. Some people don't like it, b/c it's not an actual widget, but that doesn't bother me. Hope this helps, let us know if this resolves your problems."