Can any one help me? I have a A^ 2.5TD CVT estate that has started to judder when im in slow moving traffic.

It only happens at 1st gear speed, as I start to move it feels like the gearbox is jumping in and out of gear, if I lift off and reapply it goes. Also when I am crawling along in traffic it feels like the clutch is slipping, as I release the brake and slowly apply the throttle the gearbox engages but then as the revs start to increase it seems to loose drive until I use more throttle.

I have had the oil and filters replace but this has made no difference.