Graphics ticks and motion jumping

Here's something that's been thwarting me for a long time. My box is relatively new and was just built about 4 months ago. The specs are as follows:

AMD FX-53 2.4GB
MSI K8N Neo4 Platinum
2GB PC 3200 DDR400 RAM @ 2.5-3-3-7 Latency
GeForce 6800 Ultra 256MB card (MSI production)
SB Audigy ZS 7.1 Soundcard
Yes, all drivers, BIOS, and Adapters are updated fully.

So here's the problem. In the opening cinematic of the game, when the view pans away from the console, there is a frame "jump", as if the picture is trying to cath up to itself. It happens at the pan out and also when the ship passes in front of the control tower.
The odd thing is, this happens whether I'm running the game at 640x480 with nothing special on, or 1280x1240 with high performance and everything enabled at 4x anti-aliasing (my method of playing).
Also, when I'm playing the actual game, there is a screen "twitch" every 7-9 seconds. It's as if the image shifts for a split second whether I'm moving or standing still. It is not the shuddering of the base which is intentional. This seriously bugs me and almost causes motion sickness. It has done this on both my 19" CRT monitor, and my flatpanel samsung syncmaster w/ a pure digital feed....
I have not been able to find anyone with a similar problem to mine on any tech forum online, so I'm throwing it out there to you guys.

The big issue for me is that this box can chew up and spit out pretty much everything I throw at it, but these twitches seem to be happening in all the FPS games I play (including HL2). I have replaced the video card once and the problem remained the same so that is a non issue. Someone tried to feed me that it was a data bottleneck because I was using a PCI_E based card instead of an AGP number, but anyone worth their salt knows that PCI-E surpasses AGP by miles.
Another odd thing is that on the game "Star Wars: Battlefront", I cannot begin playing the game because it does not give me an option menu to select my profile. Anyone whose played this game will be familiar with what I mean and know what I'm talking about when I say that it just keeps looping the intro video and I can do nothing. It's like the computer won't display image over image properly.
I installed it on my wife's box, and had no problem starting the game at all. Lucasarts tech support has never heard of this problem, nor have any of the support boards I've checked.

Does anybody have ANY idea what's up with this computer and these games?

You've got to be kidding, right? Not one bit of speculation?

Well, if the same shit happens in all of those games, which all use totally different engines, it means there's nothing wrong with them, but with your computer.

I'm not much of an expert, but it seems clearly you either have a conflict in your PC, or something's chewing up your RAM (which is higly doubtful, as you have twice as I do, and i run Doom3 with no problems).

I know you said you got all the drivers. But did you also check your HD for viruses/adwares? If that doesn't help, try closing all unnecessary resdient applications before running those games. Well, yeah, these are the most standard advices you can get, but seeing your PC specs I'm not going to tell you, to go to where you bought the computer and rant whoever sold it to you...

How are the internal temperatures (system, proc, card)? What kind of condition is the hard drive in?

The HDD's are twin 80gig Seagate Barracuda's running on RAID 0.

HDD's are fully scanned and cleansed of any and all spyware/adware/viruses using Spyhunter/Adaware/AVG Licensed clients. I also run sygate pro firewall all the time (but not when I'm playing DOOM).

Temperatures are fine and dandy. I run 7 fans including the 2 in the 600watt PSU and the one on the card itself.

Condition of the HDD's is fully defragged using Executive Diskeeper Pro.