I wanted to bump this because I somewhat have the same problem.
I am on BB V1.0 ROM, and I actually dont get the notification to update to FROYO 2.2. Instead, it automatically downloads a couple of times a day.
I found this out when I noticed yesterday that my battery drained faster than normal. I perused my phone and I found on "settings>about phone>system updates" that FROYO 2.2 was downloading. I had no way to stop it, nor did I hit any button to allow for it to download in the first place.
Today, I let it complete its download, and I restarted it, nothing happened, but after going back to systems update, the FROYO update is still there, waiting to be downloaded...and it will probably auto download again, as it did a few times already.
Anyone know how I can fix this? I am guessing I should just update to the newest ROM. Will that work?
Thanks in Advance.