[Moppie]

It most certianly can do. Depending on the design of the g.box it might not make a noticable differnce though.

However if your hand sitting on the stick moves it anywhere then it will be putting pressure on the slector, which wears the gear itself as well as the scynrho hub and cones.

On an older car with a very slopping shift it might not be to noticable, and the extra wear will be minimal, but on a newer car, or a car with a thight and precise shift then yes it could do some serious damage very quickly.
And the dealer could find away of showing the damage was casued by the driver and is not a manufactoring fault, and so get out of a warrenty claim. (but I have no idea on the warrenty laws in the US, or what sort of warranty the car came with)