Fast download, slow streaming!

Hi Guys,

I've recently had a new installation put it in by Speednet Scotland. They've provided me with a Ubiquiti AirRouter and 10mbps internet connection.

I've been using BBCs iplayer Diagnostic to test the download speeds. With my wifi connected I get a download speed of 10mbps, but streams at rouhly 2.5 mbps.
If I connect using the LAN I get 10 mbps download and on average 7 mbps streaming. I know the LAN should be faster.

The problem I have is when the guy set it up he used his laptop to test using iplayer and got excellent results for both download and streaming using the wifi.

I have tried a new wifi adapter 802.11n with no difference. Why is the wifi on his laptop better than mine?

I should have said that I'm running Windows XP SP3.