Arduino Mega Adk - PINE register status is not updating....

-PINE- register status is not changing (corresponding to the interrupt signal generation whenever USB device is removed). In my case, it's Arduino Mega ADK. The pin PE6 has used for interrupt based services.

Currently , I am using the soft reset function on arduino such that whenever a usb device is attached or removed, reset function is executed and arduino loads the specific driver for the newly attached device.

But now I need to implement multitasking phenomena on arduino so that I can't use reset function any more.

Can any one of you please suggest me a hint on how to achieve this without using reset function?

Thank You.