Hi,
So is it the users or the computer that the users are using, or perhaps the location that the problem users are logging in from? If it is the user, have you tried changing their access level to see if it is related to that?
Just as an aside, in the past I had a business space where the first screen was a complex presentation and sometimes did the same thing, is your home screen fairly basic or resource intensive? What are your memory settings? Have you tried increasing them?
Pete