Dropping connection when plugging in a USB device??

Curious. I first tried a "video capture device" Dazzle Fusion to
copy and edit VHS tapes. The Dazzle was powered and connected
via USB. After installing all the software, the connection with the
wireless
router/cable modem would drop. Unplugging the USB cable, the connection
would be restored. Took the Dazzle back and exchanged it for the Adaptec
VideOh capture device. This one is USB powered. Same problem.
Connection lost. Unplug the USB cable, connection restored.

Could it be that there is a problem with the wireless pci card in
conjunction
with the USB device?

Any thoughts?