Serial Comunication

Hi everybody,
I'm trying to control motors using USB serial comunication with a computer game, ex: if you lose in level 1 - turn on the motor 1 / if you lose the game in level 2 - turn on motor 2. It is already working, but with the time, when I play it many times, like 20 or more, the serial comunication stops working, and thats the point I need help, why does it stop working?

Sorry for my english and thanks for the attention and help!

The problem is in the code you didn't post.

Instead of posting the entire thing which is probably very big, try to trim it down to the smallest possible program which shows the error. Usually that will show you the error.

Sometimes this can be caused by using digitalWrite() or pinMode() on one of the Serial pins. Check all your outputs.