Hey all - Hope someone can help?! I'm a bit of a noob so I should apologise up front!    
 
I just bought a new system with an Asus P5N-T Deluxe mobo, Q6700 2.6mhz quad core and 2 x 8800 gtx's running in SLI.  
 
Whilst I'm delighted with the overall performance, and it plays games like CoD4 and crysis like a dream, I'v noticed that the gfx on some games are really jerky. In fact sideways scrolling (using the mouse on the edge of the screen) is so bad on games like Settlers 6 Rise of the Empire (yeah, I know, don't mock - it's hardly a high end game!)  that it's practically unplayable. It's kind of like it's sticking if you get what I mean.......
 
I've checked various forums and the game manufacturers sites but can't find anything to help.
 
I've tried the obvious things like turning the graphics settings down (not that I should have to do that given the machine spec), run it out of SLI mode on just the one gfx card, and updated the gfx driver to latest version etc but nothing seems to cure it. CIV4 is another example where the sideways scrolling just isn't smooth. Bizarrely CIV4 scrolls better on my old P4 2.6 with an old Radeon 9600!
 
Does anyone have a clue what's up? It doesn't make sense to me. Is it a software or hardware issue? Is there a setting somewhere I just need to tweak?
 
I updated to the latest bios version recently as well but the problem existed before I did that. It's really bugging me so any help that could be offered would be much appreciated!
 
Thanks!

Try vsync yet? It's possible that your getting too many FPS (vsync caps it to your refresh rate). Sorry if this doesn't help, but I'm not familiar with those games and their looks Could you try explaining the problem in a little more depth? Does it look like the image is tearing in half or more like it's stuttering?

your "side scrolling" issue definitely sounds like image tearing.  as monstor points out, turning vsync on will eliminate the tearing issue.  most games provide this option in the graphics area (vsync on or vsync off).  however, if it's not abvailable on some older games, you can turn this off at the driver level in the nvidia control panel.  set this to always on and let us know if it fixed your problem.

Actually you may need to turn v-sync off, people have had the same issues as you and once they turned off v-sync everything runs nice, which is my train of though, since you playing older games that can hardly tax your system, it would make sense for you to get stutter since it probably wants to scroll faster then the v-sync is allowing, anywho check it out and let us know which one it is. If the problem still isnt resolved i would have to say its simply software, these games are quite old, and it wouldnt be the first time someone had to stop playing a older game, just becuase the older software didnt mesh well with the newer hardware. goodluck.

vsync? How do I change that?  
 
Disabling the SLi doesn't seem to make a difference. Does it on just the one card which made me wonder whether a setting somewhere is wrong.
 
The problem is a stuttering I guess - a bit of smooth scrolling, then pauses for a fraction of a second, then off it goes again, then stops, but it repeats in a short period of time. Difficult to explain exactly but the image on screen is intact, just you can't move about the landscape in a smooth motion.
 
Thanks for your help btw!  

d'oh thanks all - ill try it - you all replied whilst i was still trying to explain the problem.

Doesn't sound like a vsync problem to me. Screen tearing will never make a game unplayable like the OP described.

OK I've tried forcing vsync on and off, with SLI on and with just a single GPU and for Settlers 6 at least it makes no difference - still have jerky scrolling.  
 
It does seems odd that this game features in the nvidia list of software in their control panel so preumably is being run at the nvidia recommended settings and yet still is playing up??  
 
Is there anything else I can try or should I accept this game is going to cause me trouble?!?!?
 
It may be that the vsync solution some of you have suggested may solve the problems with the other game (most notably CIV4) but haven't tried it yet...

I should add that when I said "practically unplayable" I meant because the jerkiness is sooooooo annoying, and not that you couldn't play it if you had more patience than me and could tolerate the excessively jerky scrolling...
 
Sorry, should have explained that better!

Well it has been stated before that some games will not play nice with a sli setup even if you have it turned off, unless you physically remove a card, dont know why, but that straight from nvidia.