Strange doubled lines w/ WG k7401 w/ nv geforce fx 5500 (FIXED)

[krispyfi]

Hello, all. Long-time lurker, first-time poster.

With the help of this forum, I am very close to my perfect arcade setup, but there is one last niggling problem.

In some games, some of the lines are doubled. I am not referring to doubled resolutions. I mean that the same line will be drawn twice in succession about every 3 inches or so. Text that runs across the doubled lines with have part of the letters be fat, circles (like the calibration screen for psikyo games) will appear jagged, and sprites or backgrounds scrolling passed the lines will ripple and distort. As you can imagine, I'm having a hell of a time describing the problem, let alone coming up with useful search terms to research it. The problem disappears when i use interlaced resolutions, but if I'm going to make compromises like that, what's the point of the arcade monitor, am I right?

Some games, like dodonpachi (320x240), look absolutely flawless, but others, like strikers 1945 II (320x224), have the lines real bad.

I am baffled.

Has anyone seen this problem before?

My setup:
wells-gardner 27k7401 cga arcade monitor
nvidia geforce fx 5500 pci
in windows: vanilla Mamepp with the help of the soft-15khz tool
in gentoo linux: advancemame with nvidia framebuffer
problem occurs in both OSs.

thanks,
krispyfi

[SirPeale]

Can you take a picture?

[krispyfi]

Never mind, I'm a tard.

I was expecting advancemame to automatically use the modelines i had made. What i was seeing was scaling artifacts. A little fiddling in the tab menu cleared it up. I looks excellent. 

I still don't understand why it was happening with vanilla mame in windows, but now that a have a working solution it doesn't matter.

Sorry for the trouble...