I purchased Pentax ist DL digital SLR since I had several lenses from
my old Pentax SF10.  I am happy with the pictures that the DL takes.  I
sometimes take pictures of my daughters playing their instruments on
stage and in other situations.  Generally photography is permitted but
usually NO flash.  The camera usually does OK in this situation and I
am satisfied with the pictures.  However, the shutter on this camera
seems to be particularly loud.  I feel obliged to take my pictures
during robust portions of the music.  If I take a picture during a
quiet passage in the music, I get nudges from my wife and perhaps looks
from other patrons. This limits the usefullness of the camera to me.
In normal light and outside, I am very happy with the camera.

Since I do not have any direct comparison to other digital SLRs , I ask
the following questions.

1) Does the ist DL have a louder than "normal" shutter (especially when
compared to other sub-$1000 DSLRs)?  If yes, are any DSLR cameras known
for quiet shutters so I can take advantage of the opportunities
presented to me when my daughters are playing?

2) I also like the high iso of the Pentax.  Can I get a quiet shutter
and low light shooting (no flash) without breaking the bank (sub
$1000)?

Summary:
Need suggestions for the quietest (sound of shutter or other physical
noise) DSLR with descent low light performance in the sub-1000 category
(hopefully including a decent zoom lens).  If necessary, I will
consider non-DSLR if it can fulfill the need with a descent built in
zoom). The ist-dl is just too noisy to use at musical performances.
Thanks for any suggestions.