i had problems w/ homescreen redraws on LauncherPro. the problems existed regardless of ROM: UD, BB, Sapphire. i noticed that it usually happens when i have the droid sideways running an app and then hit home to go to the homescreen. the launcher programs would get hung a bit redrawing the homescreen. i tweaked with the cache and memory settings and nothing worked. i thought, hmmm, it's not used to drawing the screen sideways.
so i unchecked Enable Auto Rotation and voila, no more redraw issues.
it might not address your problem but that seemed to work for me.