PowerBook G4 Titanium 667 -- LCD Vertical Stripe Problem

Problem: LCD displays 1 1/2-in vertical stripe on right-hand side of LCD.

Other notes:

Majority of the time, the stripe is aqua-colored and solid (occasionally a dull light-reddish color), and sometimes it flickers.
The stripe appears to blend with the underlying color, e.g., stripe that is aqua-colored on white background becomes greenish if it overlays yellow background.
Screen captures do not display the stripe.
Problem started about two months ago.
Adjusting the angle of the display or touching the upper right portion of the screen causes the discoloration to toggle or to go away temporarily ... maybe a second or two.
No problems reported with Apple Hardware Test PowerBook G4 SW version 1.2.2.
Stripe still displays whether booting from the internal drive in both OS X and OS 9, booting with the Software Install CD, or booting from external FireWire and USB hard drives ... even zapped the PRAM.