Confusing to say the least?
OK, I found the manual on the web. I'm pretty sure this is the SHAREPORT that is enabled and you have to install it on YOUR computer, from the manual,
Use this section to configure your USB port. There are two configurations to choose from: Network USB and WCN Configuration.
Note: If using the Network USB option, users will need to install the Network USB Utility into the computers to share the USB device through the router.
The above is on page 28, and this is the NOTE for it,
Note: Please see the SharePort Manual on the CD for more information.
I ran the router emulator and got to that page, and the help there is :
Select to share a USB printer, scanner, or storage device connected to the USB port behind the router with multiple users within your network.
Device drivers and the D-Link USB Network Utility must be installed on each computer that will use the device.
So, it looks like you've enabled the Shareport. Either disable it or install the drivers and utility. Unfortunately, I don't see how to disable that port? Maybe change the type? Maybe best thing to do is install the driver and utility?
HERE is an article on it.