Why must I disable my Wireless connection for Network Shares to work?

I have my WDTV Live connected to my router via an Ethernet cable.
My Network Shares work fine if my PC is connected to the Internet using the local Area Connection.
But when I enable the Wireless Connection on my PC the Network Shares don’t show up at all.

This must be a configuration issue unless your router is segmenting your network. I would recommend double-checking the IP and Subnet settings between your WD TV and your computer.