Could you also tell us the make and model of your router?

Did you try running a LAN speed test?
http://download.cnet.com/LAN-Speed-...rt=dl-6300954&subj=dl&tag=button

I've pretty bad experiences wireless especially those homeplugs. They barely broke 5 megabits.

Try wired just to see if wireless is the cause or it's something else on the network.