I'd try wireless instead of Powerline. That's a wireless router, and a wireless PCI-card in your PC.
I think I have problems on the network. I have a PC running Ubuntu 10.10 with media on hard drives shared using Samba. I am trying to play movies using an ASUS HDP-R1 multimedia player across the LAN - the router is Netgear DG834T from Sky.
I have run 3 tests, using the same path to the same movie, and taken an average of the speed readings which show up when I start and stop the movie.
Test 1 - 35226 Kbits/sec; test 2 - 15818; test 3 - 1795.
Test 1 was with the ASUS and PC both connected to an Ethernet hub in the same room. Playback was great.
Test 2 had the PC still connected to the hub, the ASUS was connected to a Powerline adapter in another power socket in the same room. Playback was fine.
Test 3 was the same but with the ASUS downstairs in a room at the other side of the house. Playback was unwatchable, stuttering and stopping completely.
There is a Netgear router with a Powerline adapter attached in the downstairs hall. There is a WinPC with another Powerline adapter upstairs at the front. The media PC is connected through an Ethernet hub (which also has a networked printer attached) on another Powerline adapter, upstairs at the back. Tests 1 & 2 were done in this room; test 3 had the ASUS downstairs at the front !
As you can imagine, at 1795 Kbits/sec the movie is unwatchable - can anyone suggest setting I may need to change, on the router for example to get better playback?.
The powerline adapters are all Netricity HD Adapter Powerline 200Mbps.