I'm using Windows 7 64-bit with a widescreen 16:9 monitor, and I'm trying to get the game to display in a 4:3 aspect ratio in fullscreen and I can't seem to find any way to do this in the emulator's settings. I have seen an option that says 'Use 4:3 Ratio' in this thread, but it doesn't show up for me even in a custom resolution: http://board.zsnes.com/phpBB3/viewtopic.php?f=2&t=14252
When I go to the filters tab in any resolution it looks like this:

I have even gone into zsnesw.cfg and changed the 'Keep4_3Ratio' variable to =1 to no avail. Is 4:3 in fullscreen not possible with this emulator?
As for the resolution problem I can't set the fullscreen resolution any higher than 1024x768 or I get this error: "IDirectDraw7::SetDisplayMode failed. Make sure your video crad supports this mode." Given that my desktop resolution is 1600x900 and my video card displays that fine I don't think that's the issue. Is this a bug or is there a way for me to get a higher resolution in fullscreen?
P.S. I saw in the other thread that there was some debate over whether 4:3 or 8:7 was better or more accurate. I'm not looking to start an argument, I'm just trying to have a question answered, so I would be very appreciative if we could avoid that debate.