Well i just did a download speedtest from the link you provided with a BF1942 demo at 133Mb.
This is what constant speed i got
http://i265.photobucket.com/albums/i...g/Untitled.jpg
Also whenever i do a speedtest with say
http://www.speedtest.bbmax.co.uk/ i allways get just short of my maximum 20Mb download but a little short on the upload usually
http://www.speedtest.bbmax.co.uk/res...1955&v=9713101
Just thought i would post so you have a bit of a comparison
Oh and i don't experience any of these "Slow links" as you described at all with DD-WRT. No difference for me than with D-Links official firmware. The main thing that sold it for me with DD-WRT's firmware is the fact that my son and i can now play the same CS:S server together. Unlike with D-Links firmware we had allsorts of strange error's were it wouldn't let another one of us join from the same network without the second person trying to get on only to get kicked all of the time. And believe me when i say i tried everything to get it working on the official firmware. It just didn't want to know...
One more thing mjpartyboy, have you checked all your power level's?