Hi i have a 20096 Audi A3 3.2L s-line and i am having a problem with the heater.

When the heat is on any tempature i get cold air under the passenger side floor vent.
now when i turn recycle on it works just fine but then i get all the windows in the car fogging up.
but when i turn the recycle with the little "A" on it it gives cold air out the vents on the bottom.

my question is does any one know of what the problem may be ?
i have been up in the mountains for the last few weeks and my girlfriend is getting pissed at me because she is always cold =P