Q: DIGITAL CAMERA RAW COMPATIBILITY UPDATE 6.21

You aren't speaking to Apple here.  This is an Apple moderated forum for discussing features, and troubleshooting. Apple menu -> System Preferences -> software update has options to disable automatic downloads, although the Mac App Store update itself for Snow Leopard does enable automatic notifications of updates.  While a nuissance, you just have to say later, and choose only to update once you have read the documentation to verify it will work with what you have.  Always backup your data before allowing any updates.

For direct feedback to Apple, which may only impact future operating systems, http://www.apple.com/feedback

If you find a specific update has compatibility issues, you are welcome to sign for a free online developer account at http://developer.apple.com and submit a bug report at http://bugreporter.apple.com where you can know at least if it is something reported before.  But you won't get to divulge that information here because of a nondisclosure agreement,

Try control - clicking on the update to see if you get a hide option.

I'm having some sort of problem with "Digital Camera RAW Compatibility 6.21" -- the little red "1" on my AppStore icon won't go away even though I've "updated" this thing 16 times!!!!!!  I hate looking at the little red "1".  How can I make it go away when I have DONE the update so many times???  Very annoying.

Hold down the option/alt key while clicking on the  menu. Select the first option. Then go to the Installation section of the report to see if the update installed. If it did, reindex Spotlight.

Spotlight – Re-index

Fascinating!  No, even though the App Store shows that I've "installed" it 13 times in a row (not the 16 I mentioned), it is *NOT* in the Installation section of the report you sent me to!  Holy cow.  Well, what the heck does that mean?  Why does it say it has been updated, but it's not updated, and how long do I have to stare at the red "1" in the dock???  I'm easily annoyed.  

If the App Store link fails, go to Digital Camera RAW Compatibility Update 6.21

Thank you a brody!  That did it!  Whew!

A good secret to remember  Google or use your favorite search engine

support.apple.com/DL followed by the name of the update.  That usually brings up the download page for the update.