Settings Don't Stay Set

Do you perhaps have some registry protection software running, like SpyBot's TeaTimer? This kind of software protects your machine by asking your permission every time a program tries to change a registry value. If you say 'Don't Allow" and "Remember This", then the protection software will never allow that program to save to the registry again. You'll need to go into the advanced configuration setting for the protection software and remove the blocks you put in.

Mine may be such a basic idea/question that you didn't mention because you thought it was self-evident, but could there be some setting in your Admin profile that is preventing the user-specific settings from being saved? In other words, have you tried setting the printer and mouse settings in the Admin account first instead of just trying to change them in the individual user accounts? Like I said, you may have already tried this, but since it wasn't explicitly mentioned in your post, I thought I'd ask. Sometimes we all have those "duh" moments; I know I sure do.