Is it the gearbox or me ?

[wannafazer]

Simon, it's very unlikely to be a gearbox problem, yes they are clunky but actual gearbox probs are rare.

Try the pedal set up. Like Ruby Racing said it could be the fact that your not letting the lever settle into its position after a change so it would need to go up. To try this make sure you take your foot from under the pedal and put it back on the peg, then try the change, that way you know the lever has gone back to the correct position.

If that doesn't solve the problem try moving the pedal down so your getting enough upshift. It's easy to adjust and a few mil makes a difference.