fuel pressure too high when cold

alright, to the basics. This is a custom turbo 4 cylinder saturn motor.
I have two fuel pressure regulators on my car, an adjustable regulator
(with a gauge), and downstream of that is a rising rate regulator. I
use the adjustable for the baseline fuel pressure at 40psi. The rising
rate bumps up to 65 under boost. All was working fine for about 500
miles. Then the rising rate regulator stopped rising under boost. And
then it got cold ouside, now when cold starting the fuel pressure jumps
up to 65 psi (which is the pump max.) Runs very rich, my wide band o2
gauge is burried at <10:1. So rich, my oil is milky with gas in a
matter of a few minutes. This only happens when it is very cold, pull
it in the heated garage and it is fine in a short time. And my fuel
line clog meter says the return line is free flowing. what does this
sound like? Anybody hear of this before? don't answer if you don't know
what your talking about.