I started off with the US Super Nintendo and an official Super Famicom S-Video cable that I imported from Japan. No matter which port I hooked it up to - directly to an S-Video port, through a SCART block to AV2 (S-Video SCART) or a SCART block to the RGB-SCART port - I got a black and white picture. After doing some reading I guessed that my TV wanted RGB for NTSC playback, and ordered a new cable. This time I ordered a custom RGB SCART wired for NTSC consoles with pure sync. This cable arrived today, and lo and behold there was color!
However, one issue remains: the picture is horriby squashed. I found a picture comparing PAL and NTSC aspect ratios for Super Mario World, and added in how it looks on my TV:

The one to the right, with the huge black area at the bottom, is what I get. Is this simply my TV not being able to handle an NTSC signal, despite the service manual etc claiming it can? Is there anything I can do about it, save getting a new TV? It's been great for all of my PAL stuff so I am reluctant to change it. It's also pretty new (~10 years old). I've looked around in the settings menus to see if there's anything there, but they're all very sparse. There's not really any way to stretch the image vertically - I mean, there's aspect ratio settings (of course), but that doesn't seem to be the problem here.
I also own a modern LCD Sony TV (w805 series) with a SCART port, but hooking the SNES up to that TV is just a flickerfest. You can barely see the picture since every other frame is black. Unless there's something obvious I'm missing there, the LCD option seems like a no-go. Besides, it has the same problem as illustrated above as well, and I'd really prefer playing the SNES on a CRT.
Any ideads? I'd be very grateful for any help!