Shuttle Noise and Heat problems with Graphics cards

hi i recently got a sb86i system, when ordering i noticed most sites offering these system builds let u customise with 7800gtx cards highest, so i thought hey if they are willing to do it as proffesionals it must be okay on the 275w psu, well i decided because of ym budget, that id get a card after a few months. Now i have added a 6800GS to the system slotted it in like i expect the proffesionals wud do and installed drivers, but it just doesnt sound right it sound like the systems struggling its so hot, and gets so noisy when playing games like cod2 and fear, is this natural wud this be the case if id got it installed by the professionals. What can i do to improve this , silencers on cards i dnt fink will fit im so confused anyone got any help for me please
thanks guys

As long as you are having stability issues I wouldnt worry. There are shuttles that have two sli graphics cards now out so one 6800gs is not going to worry it.

The card will spin the fan faster (meaning more noise) when your running 3d games than it will do in normal windows use... its nothing to worry about.

thanx guys, im not enitrely worried about it coping its just the noise it niggles at me i have never bought a high spec system pre-built so am used to pcs sounding normal and fine but modding since last year the huge sound of high ends cards suprises me and considering some places pre build shuttles with 7800gtxs and so on i wonder if they do any thing to prevent such noise otherwise it seems a little extreme, are there any vga coolers, fans or cooling hel for shuttles out there do u guys know?