YES, i've this stupid problem too.
(my00 coupe, the only mod i have is sparkco hot-wire)
i 've brought my car down to dealer last week, and left it to them for two days..and they admit that the clutch will shudder in cold start(i live in Vancouver, BC, Canada, so the temp range for last week is around -1 to 5).
and then they rearranged another appointment to check the clutch for me again...and i 've just dropped my car down the dealer 10 minz ago(12:10am)...and they will have a true COLD start in 8:00am....
i'll keep posting if they found out what caused this prob..
0.02