Why is the VW Golf Mk5 2.0 SDI clutch juddering when setting off in 1st gear?

It may be the DMF has gone, mine did the same. The DMF is the dual mass flywheel, when its replaced the clutch has to be replaced as well, so its an expensive job (£1000+), luckily I had only just bought the car so the dealer paid under warranty. Best to take it to a VW place and get them to check...