System instability when more than one user logged in

[nubietx]

Now, any time the second user (a general user account with NO admin privs) is logged in and the system is switched back to the admin account, the thing reboots.

Any ideas?

 

[nubietx]

All indications are that the 'problem' has something to do with firefox being started for both users. When I used IE for the generic user session and navigated to these same websites, the problem is not experienced.