paul, the RAM shouldn't be needed to run 4 MB games like the DKC series. They worked fine in previous versions using the paging system.
I too am having issues with loading larger games, using my Supercard miniSD. Even when I disable the option in the snemul.cfg file, it attempts to use the external RAM, causing the games to freeze.
The issue might have to do with using a slot-2 device for both RAM and storing the games. Launching the game from slot-1 while using slot-2 solely for RAM appears to work. Archeide is looking into it at the moment.
Eric, I believe the Vsync option is now labeled "Speed" and you can change between Fast Speed and Normal Speed. I'm almost positive this is the same as the old Vsync setting.