This is a 19' Proview 998N monitor. At what seems to me as random intervals
something ticks and the picture all of a sudden becomes half an inch wider
than the screen on each side. The picture "ticks" back to its normal size
again after some time or after I bump the monitor a little. If I bump the
monitor when the picture is normal size the picture becomes larger again.
Any pointers?

Tia
arch