Have any fixes been backported and have any of those fixes been released from the manufacturer?
The Xperia X10 *just* received 2.1. There's a pretty common bug in 2.1 where it can't connect to Cisco routers with a self-signed security certificate on their enterprise hardware. You wouldn't believe the number of hospitals, research institutions, and hotels have this same setup. The problem is that you cannot connect to any of these wifi networks.
From what I've read online on google's forums is that the fix was in 2.2 but supposedly backported to 2.1 several months ago. Yet, the latest entry utilizing the 2.1 OS still doesn't work.
I can see why major developers are frustrated at Android. They have to deal with phones that range from 1.6 to 2.3 (by next week) and then deal with all the variations between all the major versions. If Google is serious about a mobile platform, they need to pressure the manufacturers into updating their dev cycle and get them *all* on 2.3. It's a shame that you have dumbphone manufacturers trying to pass off their terrible OS update cycle to smartphone customers.