Well, wtf I emptied out my oil and only had about 2 quarts in there. Its supposed to have 6. Both my oil gauge and my dip stick checks said that it was in good range.
The "oil gauge" you refer to in your post is a oil pressure gauge, not oil level indicator, and it is pretty much worthless in our cars as it doesn't actually measure oil pressure.
As for the dipstick reading, are you sure you were reading the oil level correctly? I can't imagine how the dipstick could indicate "full" if there were only two quarts in the pan.
Another possibility is that you didn't drain all of the oil from the pan. If the oil has hardened into a solid or semisolid due to sludge issues, it might not have flowed out of the drain pan when the plug was removed.
Hmmm I usually jack the passenger side up a little higher after the oil has drained so I can get a couple more drips out of the pan but it's not that much.