I just got a new machine.

AMD dual core 6000, 2 gig, radeon 3870.
instaleld all drivers for motherboard, network, usb, sound and graphics.

When playing NS, some rounds can be played with no problems.

Other rounds i encounter random shuddering when i walk.

I walk then suddenly ill shudder back and foward for a few steps whilst everyone else is still walking normally, then i return to a normal pace.

I recorded a demo which demostrates what happens having some difficulty uploading it >.<

Also i'v tryed several LAN games, no shuddering. only in internet play, however net_graph does not indicate lag. iv also set my rates.

It might help if you could name the rounds causing the problems. Does it occur when you're playing the first rounds on internet, on some specific maps, on some servers, maybe even in some specific part of the game or is it completely random?

Have you tried disabling one core while playing NS? Doesn't really sound like a dual core problem though.

Hah got it.

Yeah i disabled one core, and lowered the priority as well, seems to have fixed it.

thanks anyway, see you later.

I'm having the same problem, running Windows XP Pro 32 bit, but have a 64 bit dual core AMD. How does one disable one core in XP?

Open the taskmanager.
Right click on the hl.exe process.
In the context menu there should be an option "zugehörigkeit festlegen" or "assign affiliation" or something along those lines. Click it and there you can select which cpu should run the process.

Thanks so much - sometimes Google is no help at all.