Startup smoke

[Eyvind Spangen]

My 200q20v puffs out a big cloud of grayish smoke when I start it after it
has been sitting for a while. If I drive gentle, it won't smoke at the next
startup, but if I drive "spirited", it will leave a big cloud behind. I'm
not able to see any smoke at all when driving, and I'm very careful not to
stop the engine before the turbo has cooled down. What can be the cause of
this? Worn turbo? Valve stem seals? Or just oil getting into the intake
through the crankcase ventilation?

-- 
E. S.