What's wrong with my Chip8 Emulator?

Sorry if this is in the wrong section. I'm in a hurry to get some solution, after a lot of work has been put into this. I'm writing my first emulator around the Chip 8 language, handling events and graphics with SDL/OpenGL. I just finished the last of the opcodes, and have been trying to test the emulator. At first, it would draw the first frame of the screen correctly, but then not respond. After trying to change the input, which I assumed is why there was a lack of response, to match that of an emulator I was using to learn from, it simply started crashing after a few seconds. Can anyone look at my source and give some suggestion as to what's wrong? Thanks.

Source: http://www.mediafire.com/?j689zeal6yp8lj6