This is a pretty notorious problem if you are someone who follows QC via RSS. It seems to me that Jeph updates the RSS feed manually in some manner. The primary reason I believe this is because there are often times when it is forgotten for hours/days after the comic is live and almost never updates when Jeph is out of town.
I have actually gotten over it enough that I am creating an Unofficial QC RSS feed. I'm in the process of testing that it is automatically updating properly, but if it is works, I'll post a link to it in a few days.
Also, for anyone who might be concerned out there, I am putting in the same ads that are in the standard RSS feed so that Jeph still gets equal ad revenue.