Cortex reboot issue

After establishing connection between robot and joystick, a movement of any motor using a joystick button or stick causes the cortex to reboot and lose connection. This happens when we are tethered using the USB cables or wireless using the vexnet keys. After 10 seconds or so it reconnects and is fine until we touch the joystick again. We have fresh batteries in both joystick and cortex. We also have the 9V backup battery plugged in. We are basically running a sample program from the robot C library. Any help is greatly appreciated! We compete for the first time ever this Saturday.

I am going to keep the discussion in your other thread (https://vexforum.com/t/cortex-reboot-issue-response/25064/1) as this will keep the support focused in one area for you, reducing confusion.