Mortal Kombat help

the rom stops playing when i first boot it the first time, then the second when i turn my ds off and back on, it try to play the rom but freezes. i need help... :(

What flashcart are you using, what firmware do you have installed?

im using r4 and firmware is ver1.17b

I started my no$gba and i was playing pokemon heart gold and after i did all the starting process to begin the game it freezes and it will stay there and do nothing :'(
what can i do to fix it