Yeah, sounds like a head gasket problem to me. However it can be several other things, but usually the head gasket is the problem.
Like 'altezzaclub' said, have the head faced and make sure all contacting surfaces are spotless. I had a head bolt snap on my 5K whilst installing a copper head gasket, warped the gasket removing it from the block, put it all back together and oil turned to MILK!!! Had to rip it all apart again, put a standard ACL Monotorque gasket in and she came up fine. Easier said then done unfortunately, lots of time to do it right!
Just incase you're new to this, make sure you torque the head bolts in the right sequence, then check them again after driving it for a while. It pays to clean out the thread on the block too, something I learnt the hard way (cause of my head bolt snapping!).
Cheers