Vista Business - loose all user rights

Hi,

I have a weird problem : sometimes (at random intervals) I loose all user rights. I can't open any programs (but programs that are open continue to run) , I can't access task manager and I can't get to the 'Ctrl +alt +del ' menu. If I log out and back in the problem is gone.

The error message I get says something about how I don't have rights to the files

I think It might have to do with ZoneAlarm security suite but I have been unable to prove this.

I have UAC disable and this is a new problem just started happening a month ago .

Any ideas?

Thank you