Stange problem
Try this; before you put it in first, push down on the clutch and hold it down for few seconds (5 or so) then put it into gear. I'm willing to bet that it will go right in and it wont nudge the car forward. This will allow the disk to slow down before putting it into gear. Your only getting that nudge because your trying to stop the disk from spinning soon after push the clutch in. I wouldnt worry about it, to me it sound like your car is normal.
I dont think its a disengagement issue because if the wheels were off the ground and not moving then the clutch isn't dragging.


