assigning to one key worked.

I was just playing Chrono Trigger on Snes9x, and i got to one part where there is a code that must be inputted to continue. The code involves standing infront of a console and holding L and R and pressing A. I tried this many times, and either the rom is busted, or the buttons aren't registering. I've tried reassigning buttons, and selecting "Multitap 5" in the "Input" dropdown menu (whatever that does). Nothing has worked. I'm about to try just assigning all the buttons to one button, and we'll see how that works.