PC won’t boot with usb device connected

I have just purchased a Nisis USB Graphics Tablet. With the device plugged in my PC will not start. If I start my PC and then plug the device in everything is Hunky Dory. I am running Windows 98 on a 400mhz Pentium 2 Gateway 2000 Tower PC. I Have looked on MS Knowledge Base and Gateway US site but can’t find an answer. Could somebody please help me with this? I want to use my new kit!