Problems with nVidia Resolution on Kubuntu 8.04 with KDE 4.0

[Ifeanyi]

Hi,

Ever since I upgraded from Kubuntu 7.10 to 8.04, I've been having 
problems locking in my screen resolution.  I've had to work around this 
problem by opening the system settings once I login to KDE and clicking 
on the screen resolution settings option.  If I'm lucky, this will 
resize the screen to the size I want (1280 X 1024).  Sometimes, however, 
this results in a crash of KWIN or some other display-related application. 

Also, when I attempt to switch sessions, I run a greater risk of 
crashing KWIN.  And when I do have multiple sessions running, I don't 
see the login screen when attempting to switch between the sessions.  I 
happen to know that one should be there and so I end up blindly typing 
my password and the switch tends to execute successfully. 

I'd appreciate any help in resolving this.

thanks,
Ifeanyi