jemalone,
I am a HUGE Dropbox user. It is totally invaluable for me between work and school.
I am rather new to the Droid experience. But I was quite involved in transitioning to newer OS builds on my Blackberry. I have found the same is true for me on the Droid as it was on my Blackberry when transitioning.
When installing a new OS build OTA, you are essentially installing it OVER whatever setup you have on your phone. In theory this should work, BUT you are guaranteeing yourself conflicts if your phone has all sorts of apps, settings, lists, etc. The BEST scenario for an OTA upgrade is to have your phone bone stock with factory settings just prior to the upgrade. This is my suggestion and I am making it because it is exactly what I did and my phone is running great with better battery life. I attribute that mostly to 2.2 Froyo.
1. Go through your phone and make a list of all the apps you use.
2. Research how to flash your phone back to stock. I would tell you how here and provide you will all the links necessary but certain moderators get all upset and delete my post. So PM me if you are lost. But revert to stock first, then bring your phone back online with Verizon, and bring back your contacts with Google Sync.
3. Download the new OS, in this case Froyo 2.2 Official.
4. Reinstall all your favorite apps, such as Dropbox, fresh.
This will take some time, but it is well worth it. By "wiping" your phone before moving to the new OS, you are essentially cleaning out the phone and preventing any conflicts that will result from all the upgrade patches, app upgrades, etc.
My Dropbox came back fine without a hitch and my phone is running just wonderfully.