panthera

Have you tried starting it in Safe Mode?

In case that it is a driver issue, there might be some particular graphic setting that it don't like.

Just to be certain; you're account is for the US servers?
The link pointed towards EU. Here's the link for the US support .

Regarding passwords you have 3 passwords, one for support, one for the masteraccount and one for the game. Be sure not to get them mixed up.

Have you tried <Verify files>?
If no errors, then you can try and delete 'coh.checksum' in the CoH directory and then verify files.

Related to the SP3 part, maybe updating your bios might help (it is rather old).
And just to rule out the wireless part - you also have lagged, when connecting directly to the router?

My suspection was that it could be related to the automatic search for new wireless networks (Windows Zero Configuration), but that only activates once each minute, so it seems you must look elsewhere for a solution.

Is this on XP or Vista?
And are the rubberbanding periodic? You can check that with /netgraph 1 (0 to switch off).