Blue smoke - Can't track it down!

My 2001 TD5 with 128k on the clock has been in the garage recently for quite a bit of work as during the winter it would be spewing out white and blue smoke when it was really cold. The colder it was the longer it would go on for until the engine warmed up.
It was also drinking coolent like a tramp on special brew!
So off to the garage it went and had the head removed, skimmed, a new head gasket and injector seals + new gaskets, seals and other assorted bit and pieces to sort it out.
I picked it up about 2 weeks back and all seemed fine. The coolent is no longer being drunk and the engine acts and pulls a lot better.
However, tonight the temp has dropped to 5 degrees c and once more I have the bue smoke problem. For the past two weeks it has been quite warm and I haven't seen any issues, but now it sems the blue smoke is back.
So what could it be? I'm suspecting a seal or part is worn and needs replacing, but there is no sign of rogue oil on the outside of the engine and all of the internal seals have just been done.
Could the problem be located around the turbo?
Basically, I'm stumped and any help with suggestions would be very welcome.

Do just see the smoke only when starting from cold.