Was running UD2 for several days with no problems adn then this morning I was reading the news from the News app and the phone just started rebooting over and over. I was running slayer 1ghz kernel. I went back to my UD1 Nandroid backup .
My guess is your phone doesn't like the kernel. Yes it can take a few days for it to let you know it's displeasure.
You may find this ironic (I certainly do) but, your UD1 backup also runs slayher 1.0Ghz kernel and the phone works fine. Go figure!