Yeh it's only in 3rd and 4th, 3rd more especially but again, tonite I gave it some boot on the way home and she ran fine.
My mechanic said that some oil may have gotten onto the clutch plate (he did say when from but I can't remember) which will burn off after a while, which looks like has happened in this case.
The gear box does feel fine, no selection problems and the oil was changed last year.......