Just so we're completely clear on what is going on I want to confirm with some menu images.
You start at this screen: (Menu 6 - 9)
Click "Select All" then "Delete" Confirm the delete and the list on the left is empty.
Select "Done"
When you come back in the screen is empty as shown above.
You click on Scan Locals, and see this screen:
During the scan of the 69 channels, it finds 6 local channels then goes to this screen:
Which indicates "Channels Found: 6"
But when you click "OK", you go back to the first screen and it only shows you 4 channels in the list on the left?
It's possible the receiver is failing to update the list, or it's possible that some of the channels it's finding don't really exist.
A few things you can try:
-Hook you OTA antenna to your HDTV (If it has an ATSC input) and see if the channels appear.
-If you have parental controls set, unlock the system first.
-Delete all OTA channels as instructed above then do a Restore Factory Defaults (Menu - 6 - 6) Then try the scan again.
-ABSOLUTE LAST RESORT!! If you feel very sure of yourself, and are not worried about possible negative effects, you can try the directions listed from this post
http://www.satelliteguys.us/1101407-post46.html
WARNING: If you go to thread instead of that post and follow the directions from post #1 instead of #46 in that thread you will reformat your hard drive and lose all recordings. Also note that dish sometimes changes these backdoors in updated software releases, so if after a few tries, it doesn't seem to do anything, it's possible that it won't work anymore.
-If none of this helps, and you can see the extra 2 channels from another source, perhaps you just need to have your 622 replaced.