Hi Dave,

You seem advanced, and have tried most steps that I usually recommend
however just the same, you might find my troubleshooter of some use..

With that said,  here's the checklist of troubleshooting steps for you! :-)

HOW TO IMPROVE YOUR CONNECTION:

1. Run this SPEED TEST: http://bandwidthplace.com/speedtest/

2. Download the TCP Optimizer Utility: http://www.speedguide.net/files/TCPOptimizer.exe

3. Double click the program to start it:

4. Select the type of connection you're using: DSL, Dialup, DSL (PPPoE),
   or Cable, then click "Optimal settings", click Apply changes, and click Exit.

5. Reboot and run the SPEED TEST again.  Notice any improvement?  If not,
   then the Internet "highway" that you're using may be under heavy traffic or
   construction.  I have a webpage you can use to examine that possibility:
   http://www3.sympatico.ca/nibblesnbits/TraceRoute.html

ADDITIONAL CONNECTIVITY TIPS:

1. Extra items in your Networking Properties Components list may confuse and
   delay your system while it's connecting as it has to choose which component to
   transfer the data through.  Solution: Remove unnecessary network Components.
   If you don't use dial up, replace "Dial Up Adapter" with "Network Adapter" in:
   these instructions: http://www.oregoncoast.com/configuration/ConfigNetwork.htm
* If you don't use a Dialup Modem, delete it.  In 99% of cases VPN components
   aren't used, so you can safely delete those as well.

2. Advanced Users should Reinstall ICS and Networking Components:
   http://support.microsoft.com/default.aspx?scid=kb;EN-US;q263276  Or..
   another advice would be to simply unplug the computer, remove the card
   you connect to the internet with, and then restart the computer to verify that there
   is no longer anything installed in the Control Panel / Networking section.
   Once done power off, unplug, reinstall the card, and create a new connection.

3. Lag/Latency can be caused by your Modem or Network Cards and by other
   programs running on your system.  Firewalls and even AntiVirus programs have
   been know to slow a connection down.  You can disable startup programs using the
   method explained at: http://www.pacs-portal.co.uk/startup_content.htm.

4. Scan for Adware/Spyware/Trojans with Spybot from: http://security.kolla.de
   And then run an Online Virus Scan: http://housecall.antivirus.com/

5. If you use a Router, or similar networking/internet sharing device, check for
   firmware updates.  There's been a lot of improvements with the release of DX 9.0b
   which you should download and install from: www.microsoft.com/directx

IF DISCONNECTED WHILE PLAYING:

1. Disconnects can be caused by your Modem or Network Cards and by other
   programs running on your system.  See above for help disabling those programs.

2. Another reason for disconnects could be an external router or modem that has
   overheated.  Try unplugging it for awhile, and contact your ISP to see if they have
   a newer model if the problem keeps recurring.

3. Check for IRQ sharing:  Click START / Run / type: msinfo32 / ENTER
   Expand + Hardware Resources / Click on IRQ and notice if the sound card, video
   card(s),  and modem/network cards share the same IRQ.  If they do, move them into
   different slots, to prevent bottlenecks caused by too much traffic on the same IRQ.

4.  Further to step 3., Make certain that your Network adapter or Internal Modem
   is not in the slot directly beside the graphics card, as those two must be separate.

ADDITIONAL RESOURCES:

More information on the topic of online gaming connections is available at:

http://NibblesNbitsConnect.tk my site and the reference for this reply to you includes
Ports listings, Router configuration settings, ICS, DSL, Cable and Networking help.

Dialup Tips: http://www.56k.com/trouble/#disconn
Zone.com Dialup Tips: http://support.microsoft.com/default.aspx?scid=KB;EN-US;Q228564

Hope that's been of help,  please let me know how it went. :-)