Series 80 gearbox chatter

HI

Took my vehicle to have it serviced yesterday and the mechanic asked me how long I have had the gearbox chatter. I had noticed that morning a fairly loud chatter when I had it ideling in the morning. I thought it was the exhaust system as it was pretty cold.
A new clutch was put in a few weeks ago after about 12 months of arguing with the mechanic (differrent one) that the one he put in 12 months was not acceptable as the vehicle was lurching in both forward and reverse rather dangerously when taking off on some occasions.
When its warmed up there is no noise and also when the clutch is depressed which would I suppose be normal.
The mechanic said that its not a bad problem and I if I can to put up with it leave it?
My questions are -
Is the mechanic right or can it be fixed without great expense?
Is this a common problem with series 80s.
Could the old clutch have caused some damage somewhere?
Thanks
Howard