Betson/Kortek Multisync - Composite sync issue

[MonMotha]

I have a Betson/Kortek 27" monitor, and while it works absolutely great with separate sync across all resolutions I've had need to feed it (ranging from standard interlace arcade resolution up to 800x600 progressive PC video), it does some rather odd things with composite sync when being fed standard res video (I've not tried composite sync with medium or high res).

Basically, the fields "tear", especially at the top.  You can see that the two fields are notably not aligned, and they gradually come back into alignment as you go down the screen.  It did this on both the output from a Konami S573 and a PS2.  Separating the sync from the PS2 fixes this issue.  It *looks* like the monitor is finishing the vertical retrace too late (with the sweep somewhere in the middle of the screen horizontally) on one of the fields, and getting the other field correct.

If there is a known fix for this, that would be great.  Otherwise, I can just build myself a sync separator for hooking up standard arcade boards.  It just seems silly that I'd have to separate sync when the monitor clearly is at least somewhat capable of doing it on its own.

I've also got the purple blotch in the upper right corner that seems fairly common.  I'm under the impression that using a degauss coil and doing the standard "dance" can fix this?  The built-in degauss certainly doesn't do much to help.