I've had a few problems that sound similar to what is happening to you. Except my unknown device was called PCI Bridge. I finally figured out that the mysterious device was my on-board infrared connector. When you update the driver in device manager, try making it a "Built-in infrared port on laptop or desktop." It worked for me.

Good luck,

Steve

BTW, this only seems to happen in Win95. I set up a Win98 machine with identical hardware and Device Manager didn't show any mystery devices.