Stopped Megaman X6

When I download Megaman X6 at romulation.net and try it with my emulator sometimes it's stopped but start again, then I choose a mission then stopped and never start again.
What's going on??
What's wrong??
I'll really appreciate if someone could help me.

What emulator do you use ?
Try to use ePSXe 1.7.0 to play it.Here a tutorial to configure it http://forum.romulation.net/index.php?topic=8528.0