pegasus isn't alone...only one Hilton stay of mine has ever posted to my HHonors account automatically. I've had to scan the hotel bill and email it to them every other time.
mind you, I usually get my points within 1 or 2 days of emailing them, and there's never been a discrepancy.
I wonder why, in the modern age of computers, nobody's designed a system that can give instant credit once payment clears?