Well I just got a second 8800GT and DDO is supposed to be SLI enhance according to Nvidia website and I see no difference in frame rate what gives?

did you enable sli? also you should know that sli doesn't scale all that well. what resolutions are you playing in? maybe it's bottleknecked by the rest of your system.

Its your flux capacitor.  Use your mister coffee to give it more juice.
 
You realize that you gave us no useful information right?  Other then "SLI don't work", what are we supposed to know about your setup?  Game settings?  What FPS are you getting?  Throw us a bone, and we might be able to give you a real answer.  

E6300@3.08
3GB DDR2 XMS 800
EVGA 750i FTW Mobo
2x8800GT Stock clocked
 
Settings are at 8x AA 16xAF 1440x900 everything max FPS 35-100  
Same as it was with one 8800GT and yes its enabled.

not all games support SLI.
TELL US WHAT GAME IT IS!!!!

DDO = Dungeons and Drgaons Online!!!!!!!!!!!!!
http://www.slizone.com/object/slizone2_game.html

PSU maybe?  
 
I don't have any experience with this game, does it auto patch when you load it?  (online, I would assume it does...)  Have you tried updating or changing your drivers?  Seeing as its an online game, there might not be anything you can do.  If you hit 35FPS in a heavy action area, your internet speed probably slows it down more then anything else.  The fact that you can hit 100FPS shows your system as a whole is good enough.  Whats your upload speed?

8/Mbps 1.5/MbpsS is my speed my PSU is Corsair 520HX 40a Triple Rail so I think its good enough.
Yeah i got the new nVidia driver that came out today and the game does auto patch.

well duh! its only the most popular game ever!
 
some games have a FPS cap.

You are kidding right?  Unless I am mistaken, That game works with a GF2 and a Geforce FX or Radeon 9800 is the recommended spec.  What do you expect SLi to do for you when a single 8800GT is 10 times the recommended card?

Have you ever used SLI? It can scale amazingly well if you know how to take advantage of it.  I see 50-80% in parts of crysis at the settings I play at. Oblivion I can see higher than that in the most GPU demanding outdoor Foliage.  Downright close to 100% scaling even.  SLI provides decent gains in the vast majority of games now.  You may not always need the second GPU depending on the game and resolution, but that doesn't mean it scales bad.    
 
Take a look at the fps in these merged screenies of single 8800GT vs dual 8800GT.  I compressed them to fit on imageshack, but they are still pretty huge.  
 

 

 
Chart of fraps benchmarking fps of  actual Crysis gamplay in paradise lost single 8800GT vs dual 8800GT.  If I had enabled 2xaa, the % scaling would be larger.  
 
 

 
My experience with LOTR Online might be helpful. It's also a Turbine game. In fact, my wife and I went lifetime this month.  
 
Anyways, when I remarked that I wasn't getting Crossfire with my 3870x2, I was told on the boards that for some reason, LOTR Online doesn't do SLI or Crossfire all that well, that people even turn SLI off to get better performance.
 
I'm quite sure DDO is in the same boat. It's up to Turbine to fix it. Let's hope they do. So bring it up on the boards for your game and maybe the devs will listen.
 
Several of my single player games do show Crossfire improvements about equal to that in reviews for those games (ie The Witcher, Oblivion), but the one game I like the most just acts like there's only one GPU present.
 

 
The reviewers mostly say that SLI doesn't scale as well as Crossfire, but that's a driver issue that will improve over time.
 
I'm glad more games support both Crossfire and SLI and I see multi-GPU cards like the 3850x2, the 3870x2, the 9800gx2 as the future. It's just up to developers to actually support them, as well as for Nvidia and ATI drivers to optimize performance.
 
It's just that from what I've read on boards regarding Turbine's 3 online games, they don't support SLI or Crossfire all that well.

Depends on the reviewer.  FS typically enables fsaa and sees great SLI scaling in any game/setting that isn't CPU limited. http://www.firingsquad.com/hardwar [...] /page3.asp