hi just recently bought a skoda octavia 2.0tdi 140 bhp after 3 weeks of having it dualmass clutch started rattleing so i took it back to garage he was great about said he would put me another clutch in ,he said do u want conversion kit in ,i said yes he put that in after a day there was alot of vibration and it kept grabbing in first, second  reverse ,so i took it back he drove it and said it looks like the car dont like the conversion kit so he said he will put a dualmass back in it and i would have to pay the labour to which i agreed , picked it up seemed ok for a day then started grabbing gears again so i rang him he just said it cant have been clutch .so he said try changing gear box oil to which i have done , it still the same,i changed master cyclinder today .still the same anybody any ideas running out of money and patience

Sounds very similar to the problems I was having with my 2.0 PD140 6 speed

Have a look here

http://www.briskoda.net/forums/topic/322278-very-strange-clutch-issue-any-help-appreciated-please/#entry3869051