This looks more like a video-termination problem.
Old glass monitors (video or computer) have 75ohm termination resistors on the video input, or 1 each on the R,G & B signals etc...
In many cases, certain brands of modern LCD's don't have the termination resistors fitted (or different values).
The smeary effect is typical on a non-terminated signal, and will vary on various levels of brightness on your screen, hence the fault "coming and going".
It will show more on the hi-score and feature displays as they're the brightest parts of the display screen, and probably being fed with a full 2volts of video signal instead of 1volt required by todays LCD monitors.
Perhaps a few searches on google about video temination and/or RFM 'smearing' problems will come up with a mod, but it's basically just fitting 75ohm resistors onto the R,G B signals of the video cabling....
The resistors ensure that a 2volt signal (the old crt signal) appearing on the video/vga inputs is reduced to 1volt standard.
hope it helps.....
