Windows XP Pro keeps creating users’ a temporary profile.

I’m an admin on an AD domain. When some of my users log on, Windows says it cant load their profile so it creates them a temporary profile. I would believe this to be a corrupt profile but it happens to them on more than one machine… but not all the time. There is no consistency with this error. We don’t use roaming profiles so i don’t understand why this would happen on multiple clients let alone so sporadically. Anyone come across this issue before?