I tried this new feature on my upgraded iPone 3G yeserday - what a mistake. It took my main smart playlist (which had about 1/3 of my tracks checked) and added all loaded songs to it. I can't find a way to undo this from the iPhone or iTunes. iTunes still shows 782 songs selected, the iPhone shows 2345 songs on the same playlist.

It makes me wonder if Apple does enought testing on the upgrades before they release them. Hours to complete the first back-up - still no "mark all read" ability or aliases on the email app. - etc.

Anyone have any ideas on how to undo this damage?