inserting g_serial at boot time

Hi all

I am using g_serial module of BeagleBoard …to use usb port as serial port to communicate with windows Desktop.

i have inserted that successfully …
but for using it …

i have to power on BB/BeagleBoard without usb cable connected to PC …and then i do modprobe and then i can use usb as uart …its ok.

But my project requires BB to boot while usb cable is connected to windows …and if i power on Beagleboard with usb cable connected to PC …
then while booting kernel panics on beagleboard side…

please tell me …

1)why does kernel on BB panic if usb is connected to windows PC

2)can i do modprobe , on BB while booting up …at such point of time , so that it does not panic…

how do i do that …

please guide
Thanks
Nidhi