Question : Problem: Laptop screen inteference

I have a laptop (Specs Below) which i have been having trouble with for the last year or so.  The problem is a screen inteference - light areas of the screen flicker in and out and eventually go a aqua tint.

Compaq Evo N1000c
Radeon 7900
40GB HDD
2x512 Kingston RAM
OS: Gentoo Linux

At first i thought this was a simple failing of a colour (im used to CRT's failing) but it isnt - its more of a interference.  Upon inspection i can see Red, Green and Blue colours when the display fails.  The screen has faint darker aqua lines that run up its length (Bottom to top) that look around 5mm apart that are visible in grey areas of the screen.  Light colours are tinted but darker colours are not so much.

However - If the screen is filled with darker colours on the majority than the ligher colours it snaps back to normal.

Ive tried swapping the RAM (1 out at a time) to no avail.  I have also tried taking screenshots and viewing it on another computer to no avail as well.  The picutres are fine.

I have had this problem both in Linux and Windows XP - its not a drivers issue IMHO.
This problem doesnt occour untill the OS picks up and begins to load - XP started doing it at the animated logo loading screen and Gentoo Linux does it ~30 seconds after i load into X/Fluxbox.

Any details i have left feel free to ask - excuse the long post but its hard to describe the problem.

Answer : Problem: Laptop screen inteference

If you hook up a external monitor and it works just fine,  then I'd suggest resetting the connecting cable.
There is a cable that runs from the screen down to the motherboard that if the screen's been pushed back past the recommended angle can come loose or get damaged.  IF you are good with the disassembling and reassembling of the unit, ( you can sometimes find documents on how to do that on Compaq's website)
then I'd suggest disconnecting and reconnecting that cable.  If your cable is damaged you can easily replace it through either spare parts or a used equipment vendor.
Sandra