I also believe Piriform is doing the correct thing when removing restore points, as they are rather touchy things - especially in XP.
If people want to clean restore points in xp, best way is to turn it off, turn it on again - deleting them all. (a simple script can automate this)
Yeh as far as i know too, the only way to clean this is the delete the old registry key and restart explorer.exe
I thought ccleaner tray notification cache option would do this, but it certainly doesn't.