is it just me or i don't see any driver in the car? 

Maybe read this will change your mind
http://www.scottkelby.com/blog/2009/archives/5202

Scott Kelby actually sold off his D300 after he purchase D5000

of coz it can half press to focus first...

the beep u can set in the settings...
d5000 body only ka or kit?

since u bougth body only, i assume u using your old lenses?
using non AF-S lenses or using manual focus maybe is resulting in wat is happenning to u
cos when dun have/not using auto focus, the cam will usually snap right away i think

jz to b sure, ppl can make careless mistakes sometimes
jz check wont hurt, is your lens set to AF mode or MF mode?
not thinking u noob here, but there's a possibility u forgot... 

if it is in AF mode, then i dunno wat else can cause the problem
better send for checkup...

better send back to shop to check the prob la...it shouldnt do that

he change the body for you? sounds fishy..

1. If he sends it for warranty to NIKON then the BODY serial number MUST be the same as before..

2. If he really replaces it with a new D5000, REMEMBER TO CHECK the image number... he could easily swap it and changed it to the demo/used unit without u knowing. If he formats your card then the image number will be zero again..

3. SO to be absolutely sure, after u get your camera..go back home, check the shutter count..if the shutter count is much higher than the number of pictures you tested/took at the shop, then it could be a used/demo set.
e.g. PIC TAKEN: around 30 shots , REAL SHUTTER COUNT: 120 shots

Check the shutter count using this program : Opanda IExif
http://www.opanda.com/en/iexif/download.htm

4. IF he really change the body to a new one:
- Make sure serial number on card same as on body.
- The shutter count must be zero bacause it's new and because this is body only..no lens attached..
- Make sure the body has no scratches at all even slight ones..
- Make sure the neck strap is not attached when the box is opened, because it will be separate if new (when i bought D60 & D90 like that)

so how did your case go?

hi~
newcomer here...just got my d5000 yesterday ^^
hope can learn more here