Why is my nvidia 9800 GT slower then my 8800

Which 8800 was it ? Ultra? GTX? GTS? GT? GT KO?

Basically you didn't upgrade at all, a 9800GT is pretty much a rebrand of a 8800GTX i think.
Although you shouldnt be getting less performance, did you remove all your old drivers before installing your new card?

8800=9800=250(+5%)
why didn't you ask before you buy?

On paper and in real life they are exactly the same.

If you have had a 8800GT,then a 9800GT performs like a 8800GT(slightly faster)
And if you had a 8800GTX/ULTRA,then 9800GTX/9800GTX+ perform like that and 8800GTX/ULTRA is faster than a 9800GT(128 SP's vs 112 SP's)

You are so wrong it's beyond funny, rather than just believing the ATi fanboy rhetoric why don't you try looking for the actual facts first.

You got conned by Nvidia, just like millions of people before you. Be sure to buy ATI next time, they don't rebrand the same card with higher numbers.

It's not going to make any difference to their market share, but then again they do need all the help they can get.  

If you can, send it back. But you will take a 15% re-stocking fee hit. If you can convince them that you will buy another card in place of the 9800GT, then they might waive the re-stocking fee. Note that you will have to pay shipping charge for the 9800GT.

Alternatively, you can try to ebay either card.

Which 8800? It probably wasn't much of an upgrade, and if it was an 8800GTS 512, GT, GTX, or Ultra, it wasn't an upgrade at all.

Thats why I said "i think" because I wasn't 100% sure, lol   whats the ATi fanboy rhetoric?

Yup, the 9800GT is exactly the same as the 8800GT (well, some of the newer ones have a smaller 55nm chip, performance it 100% the same though).
If you upgraded from an 8800 GTS 512, 8800 GTX or 8800 Ultra, your performance is now lower.
If you upgraded from an 8800 GTS 320/640 your performance is just a tad higher.