SGI: Video

O2 Composite video input from old computers - sync timing?

My O2 is working fine capturing video on the composite input from new devices, but refuses to capture more than one fairly unstable frame each time I plug it in and out of an old computer (an MSX 1 in this case). I note someone else had a similar problem with an Amiga 1200 and a Commodore 64, so I'm guessing this is a more generic issue.

Is it possible to easily fix either the O2, or the home computer, to fix the signal as appropriate? It's a pretty old box (1983) and only outputs RF, Composite and mono audio.
Have you tried using a timebase corrector?