Visible lines on my LCD screen (Refresh rate problem?)

[mrwolff]

I'm not sure if this has to do with refresh rates or not, but I can see 
little visible lines running across my screen sometimes.  It isn't 
visible a lot of times, but for example with gray backgrounds or 
something similar it is very visible.  I would say it was something 
wrong with the refresh rates, but this is an LCD monitor on a Dell 
Inspiron 6000 laptop.  Any ideas what they are or how I get rid of 
them?  I checked my xorg.conf and did notice that the monitor was set at 
1280x800 at 60

I'm not sure what the @ 60 does, but could I perhaps change that and get 
rid of these lines?  What are the standard settings for an LCD monitor?  
Do they even need refresh rates?