I was having the same problem. Constant force closing and restarts and the phone was slooow to unlock. I uninstalled Launcher Pro and the Unlocker then reinstalled both. Haven't had any problems since.
I agree that the answer may lie in uninstalling LPP and then re-installing it. Had the same problems after the Froyo update and this solved it. Also, from time to time, LPP gets fussy and an uninstall and re-install usually takes care of it.
I've been having some problems with LPP lately ... previously, it was working fine for long periods. Now, though, it will give me broken screens, missing wallpaper, frozen screens, and the need for a force close, off/on or battery pull. Seriously considering removing it for a while. Not sure why it's become so unstable. Oh well.