Could I have help to improve my MN download speeds?

[#1]

Hi,
I have an Metronet PAYGo Option 2 service that I feel should be running faster. I'm only half a km from the exchange (which is showing green) and I'm getting the following results:
BT Speed Tester
    IP profile for your line is - 7150 kbps
    DSL connection rate: 448 kbps(UP-STREAM)  8128 kbps(DOWN-STREAM)
    Actual IP throughput achieved during the test was - 5619 kbps
Thinkbroadband Speed Test
    Speed Down  5074.77 Kbps ( 5 Mbps )
    Speed Up 376.00 Kbps ( 0.4 Mbps )
    Port 8095
    Server speedtest1.adslguide.org.uk
I once got up to 6Mpbs, but I can't remember ever seeing it any higher.
I've read James' excellent article "Broadband Speed Faults: How to diagnose?" which indicated that it might be one of several problems but I'm unsure how I should progress. My connection is stable, it's just not as quick as think it should be given the high synch and IP Profile speeds.
I play a lot of XBox Live games and was wondering if interleaving could be disabled to improve both my gaming and my BB speed?
Or should I just be thankful for the speeds I'm getting? 
Many thanks,
Chris
------------------------
MN Account name: basirk

[#2]

Try tweaking your MTU and RWIN values.

[#3]

Chris,
As per Peter's comments, have you tried tweaking your MTU and rWin using Dr.TCP?
I'd suggest an MTU of 1430 with a receive window of 113440.
You can download Dr. TCP from here:
http://www.dslreports.com/drtcp
Let us know how you get on.

[#4]

Remember as well that your direct distance from the exchange does not necessarily correspond to the line distance. The actual cable could go a mile up the road and back down for all you know.

[#5]

Hi Denzil,
Basirk is syncing at a speed of 8128Kbps so the distance is not an issue here.  It may be down to exchange contention or something that can be tweaked to improve the speed that he is currently seeing.

[#6]

Just in case anybody with speed problems is using Vista, the tweak site http://www.dslreports.com/tweaks doesn't recommend tweaking for Vista as Vista has a tweaking system of its own built in.