My acer has developed vertical white lines on the display. I saw this behavior a few times before, but applying a little pressure behind and to the right of the lens area always made it go away. Now it's persistent. If I apply quite a bit of pressure, say around 10 lbs, it will go away, but the moment I release they come back.
I also noticed something new - applying pressure at the projector mount screw hole points causes additional white lines to appear.
For what it's worth, the lines appear regardless of input, resets, etc. They appear with no input at all. Also, the machine has been in its ceiling mount for basically its entire life. It couldn't have developed this issue from being handled roughly or heavy portable use.
Some net research seems to conclude this is a failing chip or connection issue.
It's still under warranty (purchased Nov. 2012) so I'll let everyone know how the warranty experience with acer goes.