Nop my gearbox is sweat as a nut, goes into to gear fine just crunches as above.
Any crunching from the gearbox is not good, I would take it back if its still doing it and demand its fixed, take one of them out and show them what its doing.
It will only get worse and you don't want to be stuck with a big bill when it goes completely out of warranty.
I have found that ringing RUK gets the ball rolling rather quickly, not the best way to makes friends though.