SO, if you've gotten an RGB modded PCE of some variety and you notice that there is this f*cking annoying bend at the top of the screen, here's what you do.
http://junkerhq.net/xrgb/index.php/XRGB-3 Go to Special Screen Settings.
Set the NTSC AFC to manual
then, change the value back and forth until the bend goes away.
I Used 4, and it produces a perfect image now.
Why the PC Engine is the ONLY RGB console I own that requires this is beyond me, but now you know!