Arcade Monitor - Native Resolutions. Little confused.

[CaptainAfro]

Hello everyone. I currently have a 19" arcade monitor, WICO SUM-20C, connected to an older computer, video card is a Geforce 5900 XT. I ordered one of these: ([url]http://www.ebay.com/itm/VGA-TO-CGA-CVBS-S-VIDEO-CONVERTER-PC-to-VGA-GBS-8100-video-game-converter-/400635702172?pt=LH_DefaultDomain_0&hash=item5d47bfab9c]http://www.ebay.com/itm/VGA-TO-CGA-CVBS-S-VIDEO-CONVERTER-PC-to-VGA-GBS-8100-video-game-converter-/400635702172?pt=LH_DefaultDomain_0&hash=item5d47bfab9c]([url]http://www.ebay.com/itm/VGA-TO-CGA-CVBS-S-VIDEO-CONVERTER-PC-to-VGA-GBS-8100-video-game-converter-/400635702172?pt=LH_DefaultDomain_0&hash=item5d47bfab9c[/url]) to connect the monitor but right now, I have the 6 RGB wires (R,G,B,GND,H,V) plugged straight into the VGA connector on the card (Probably not terribly safe).

I installed Soft15khz and I'm currently running at 800x600 just fine. If I change resolutions using Quickres, I have to adjust the V-HOLD. Only 640x480 works after adjusting, anything else I can't adjust enough to stop the vertical scrolling. How can I get other resolutions to run without having to open up and adjust the pot? I'd like the lower resolutions for MAME obviously, but possibly higher resolutions (Max on this card is 1280x1024) for a few PC games I have on there, like DJ Max Trilogy. Would appreciate any help or advice.

I should note, I'm currently using MAME .149 modified for CAVE SH3 driver, Hi Score and No Nag.