'03 Elantra GLS A/C?

I have an '03 Elantra GLS. It has about 8,500 miles on it now. This is
my fourth Elantra: 1997, 2001, 2002, and 2003. I understand completely
how the A/C works and how it comes on with the defroster. I also know
that in 2002 and earlier models you could turn off the A/C in defrost
mode, but now you can't. Fine, I can live with that.

But what has been happening with this '03 car is unacceptable. The A/C
comes on ALL BY ITSELF sometimes when I start the car. This happens
irregardless of the position of the air, and I have not been in defrost
mode for a few months now.

Imagine my surprise the other day when it was -2F outside and my A/C
compressor turned on.

Now it doesn't happen every single time I start the car, but it happens
more as the temperature is low.

Up until last week, it was a mild winter here in NJ, and whenever I had
the car to the dealer for this they could not reproduce the problem.
When the ice age hit last week it was happening on every start. I made
an appointment for the dealer today and guess what...it is almost 40F
again and they can't reproduce the problem.

Has anyone else had this problem? I can turn the A/C off by pressing the
button, but sometimes I can ride half-way home before I notice it is on.

Any good technicians out there? I haven't looked yet, but can I just
pull the A/C fuse until I can get the dealer to find the problem? Is
anything else on that same curcuit?

Thanks for any and all ideas.

Eric

P.S. - I know what you are thinking and NO I am not hitting the button by
accident. I am quite sure this is something either with the computer or
with the built-in temperature sensor.