Okay guys. You don't necessarily have to be so hard on yourselves. Was there another aircraft in front of you on the approach? As a long time CFII I can tell you that there have been instances of when another aircraft is on the approach directly in front of you and exactly on LOC and GS, the hull of the aircraft can deflect some of the transmission from the antennas to make you think you're wacky. I don't necessarily condone this, but sometime fly the approach about a half dot left/right and half dot high. You just might see a difference.