Oh! Hey, give it a day or two because they are screwing around with that bird and so there is nothing we can do on this end that would be of any good. Sorry for the wait, but I have no control over their idiots at the Level III who should be in the room to begin with. Right now, you are amoung about 12,000 customers running the same speed. The other half are getting awesome speeds over 1.3Mpbs (average). I'll let you know when things change, or pls let me know asap when you observe a change for the better.
Since you have applied all tweaks, did you also download and install TCP Optimizer PLUS Dr. TCP only to turn Time Stamping on? I've included them (attached) to save you at bit of searching.
Here are the most successful settings for Dr. TCP:
TCP Receive Window 0
Window Scaling No
Time Stamping Yes! (helps with latency)
Selective Acks Yes
Dial Up (RAS) MTU (el blanko)
Path MTU Discovery YES
Black Hole Detection NO
Max Duplicate ACKs 2!!!!
TTL 64
Adapter Settings should be for whatever device is listed in that box that is listed. If you have a LAN and Router, use your NIC. IF not, use whatever it detected, set the MTU to 1500 and SAVE wherever your like the exit. Leave that in your machine no matter what.
-----------------------------------------------------
For TCP Optimiser (from Speed Guide) <---has more toys!
First, click on FILE, then select "Backup Current Settings" just in case you get dusted....
On the mid-line of choices, set it to Extreme
In the Netowkr Adapter Selection, most likely your NIC will be displayed and that's what ya want
Everything should be pretty much ghosted when set to Extreme
Set the lower choice to Optimal Settings
Under the MTU, you can let it check for you by clicking on the start, but ALL of DWay uses an MTU of 1500 for DW6000s especially (some 4000s are better off with 1460 or 1480.
On the Latency/Ping tab, "modify" it so that your favorite haunts are listed - - plus
www.google.com and
www.cnn.com this will give you an excellent number to reference for your config!!!!
Double check to make sure it is still set to Optimal Settings, Apply Changes, then reboot that puppy, get on bended knee and pray for the best when you test again. You SHOULD see an increase, but if not, it will get better over the next very few days. If not? Dig me up and we'll take that sucker apart. C4 ....everything.

Cheers!
The Reverend