gray screen when using usb modem

Howdy.
Something strange happened to my Mac,
I use a USB modem by Orange il. Mac recognized it with no problem and installed the installation package.
After installation when Mac recognized the modem again a gray screen appeared and asked to do Hard Reset.
I'm using Snow Leopard 10.6.2 and I had no such problems with it.
It happened to me once when I had version 10.5 and changed Drivers for usb to use Dfu.
I checked the computer, and to be sure I downloaded the new drivers and reinstall it and it still happens when I insert the modem.
As soon as I uninstall the modem I can insert it without a problem until I install the drivers and then this Crash happens again ...
Anyone have a solution? I'm really stressed about it if someone can help ... Thank you.

 

anyone?