GPIO Interrupt problem of AM335X WinCE7!!

Hi, TI Technical Support:

I am working on TI's AM335X running WinCE7 on it.

I found one problem, GPIO Interrupt set problem. When I configure GPIO1_20 as a GPIO function, and set it as an interrupt line of my touchscreen interrupt using API 

GPIOSetMode(GPIOHandle, GPIO1_20, (GPIO_DIR_INPUT | GPIO_INT_LOW)), after building the WinCE kernel, running it on AM335X , the system will hangs there.

But if I set GPIO as : GPIOSetMode(GPIOHandle, GPIO1_20, GPIO_DIR_INPUT), just remove GPIO_INT_LOW, the system run into WinCE desktop successfully.

This is very strange! What is the matter of GPIO interrupt API? 

Would someone here meet this problem?

TI Technical Supporters would you help to check and solve this?

Thanks in advance!

Stephen Zhang