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.....
Is this what you would be talking about Marty Machine? This is about all I could find that remotely helps or could remedy what you are talking about
If your PC does not sense your monitor it is likely your monitor is not loading the RGB signals. Measure input resistance from one video signal (R, G or B) to ground with an ohmmeter, in 200 ohm scale it should read around 75 ohm. Some monitors have a switch or jumper to enable loading of video signals, if yours does not have this setting you can add three 75 ohm resistors from each video signal to ground as shown below.
