1996 Other Suzuki Models clutch over hauled and wobbling sta

I got my maruti suzuki zen car's clutch assembly over hauled two days back. After that I am experiencing a full car vibration that I can feel (assume) as it is from the front part of the car when engine is loaded. I mean if I am accelerating, I can feel the vibration and everything settles down to be smooth once the clutch pedal is pressed (no matter what ever the running speed is). It seems the vibration is directly proportional to the Engine RPM and also only when the engine is loaded.
The mechanic who overhauled my clutch assembly tells that it is because of the drive shaft problem. Then my question is how it come all of a sudden and not when clutch pedal pressed? Please give me a suggestion..
J John