http://www.netgear.co.uk/home/produc.../XAVB1004.aspx - This is the powerline adapter kit I have. Netgear is the make and the model number is XAVB1004.
It's been going on for about a week now. I have only been at this house for one week as well. It's been like this since day 1 (which is when the powerline adapter was installed). Previously we have had other issues with the router which is why Virgin installed a Superhub. I believe other devices are able to connect to it wirelessly without any problems whatsoever. I do regular speed checks on my iPhone and seem to get great results at all times.
Yes, my computer is the only device that connects to the powerline adapter.
Here is the DHCP Lease Table for our network:
IP Lease Table
Device Name IP Address Expires
Lukes-PC 192.168.0.6 30-Dec-2012 14:11
User-PC 192.168.0.3 30-Dec-2012 22:31