Are you in 4Wdrive? How many miles on this Sorento? Did you buy it new? If
bought used did it come with any warranty?

I found out from my dealer that there is a known problem with the earlier
Sorentos involving the drive shaft, transfer case or both.  It results in a
"clunking" noise upon moving after braking to a full stop as one would do at
a traffic light.

The first step is lubrication, followed by drive shaft removal and repair if
the lubrication does not work.  I don't know what they do in the case of a
faulty transfer case.

There might even be a technical bulletin on it, at least in Canada but I'm
not sure about that.

Hope this helps!

Go to this site and you will learn alot about your Sorie...

http://www.sorentosite.com/

It is a great group

http://www.sorentosite.com/forum/showthread.php?tid=1079

OK, here's what the bulletin says, word for word.

Some Sorento owners may complain of an intermittent
"bump" feeling when coming to a quick stop or
pulling out after a quick stop. When this occurs the
driveshaft slip joint may be binding from lack of lubrication
on the splines at the slip yoke. To repair this
condition remove the driveshaft from the vehicle,
mark the driveshaft orientation for balance purposes.
Separate the driveshaft halves, apply valve grinding
compound (Permatex P/N: 34A) to the splines, work
the driveshaft yoke back and fourth approximately 40
times to buff the mating surfaces. Thoroughly clean
off all valve grinding compound from interior and
exterior splines and apply a thin coating of Steelco*,
Industrial Lubricant P/N: 488-1 Red Crown lubricant
or equivalent to the splines. Reassemble the driveshaft
and road test to verify proper operation, replace driveshaft
if condition is still present.

Hope this helps.