I posted this direct to support shortly after buying the BDP5100:

I have updated the firmware for this player but its capabilities are very much less than advertised. It will not adequately find folders on my networked PC. It will not access some folders at all and when it does it doesn't display files names or photos properly; it continually locks up. Displaying photos from a USB memory stick suffers from very similar problems and it is ponderously slow and keeps locking up. There appears to be no facility for accessing Net TV or the web which the product description says is possible. Why not? I am extremely disappointed in this product's performance against its specification.
Reply I got was:
Do a system re-set
• Press and hold the power button for 10 seconds keep you hand on the power button and unplug the power from the mains unit and leave for 30mins
• Take out the batteries from the remote and leave them for 10mins then re-insert
• When you put the mains power plug back in hold the power button
If these steps don’t work then what I would advice you to do is contact our customer support team on the number provided below for further assistant or to arrange for an engineer to have a look at your Blu/ray player.

This was of no help whatsoever. I am networking to my Laptop via ethernet cable and powerline adapters connected to BT Home Hub 2.0 router. Has anyone any advice as to what I need to do or what I am doing wrong. The manual is of little help. I note that a USB adapter WUB1110 is necessary for wireless link but signal is week, that is why I am using powerline adapters; surely that should work?