2.1 had an option to set the slide lock to prevent unwanted screen presses. I always set that (have done it since my very first regular non-smart phone a decade or so ago) because you do NOT want your phone to dial your Mom when you are discussing inappropriate topics! 2.2 seems to have this on by default with no way to disable it.
Then again, I also always set a numeric lock since the phones have a lot of relatively sensitive data on them including cookies or saved passwords that log me in automatically to various sites and stuff. Even though the lock can eventually be defeated, it's a small layer of immediate security.
So I use both and have gotten so good at it, it only takes about 2 seconds to unlock the phone, I don't even think about it any more. I recommend the numeric/pattern/password lock regardless of there being a slide lock also. It's really a safer way to go.
This has got to be a software item that changed so it sure would be nice to know what that setting was and be able to change it back so you could indeed disable the slide lock since there's no reason it should have been removed (the option that is). Of course, you'd probably have to be rooted to do so which is silly.....
By the way, I updated with the OTA but did have the slide lock already on so I don't know for sure if the option was still there right after the update. I also performed a factory reset a day later due to WiFi issues which did not fix the WiFi issues but did seem to work out the small issues in sluggishness I saw immediately after the update.
My plan next time is to back up my data, do a factory reset, take the update, do another factory reset and then use the phone. I'm thinking that using a phone for some time and applying an update is just as bad as using XP for a couple of years and then upgrading to Vista or W7. Upgrading is almost always a pain because it's carrying forward crap better left in the past. Just like with a PC, it's probably good to start from scratch now and then.
Kevin
...just kidding - well hopefully the OTA will fix it for ya...