indeed, i have cruchy gears too when cold.
in the winter its very noticeable, but in summer i hardly notice.
i tried using a product called slick50 to smooth things up, it did work for about a month then went back to norm.
i have considered draining the gearbox and re-filling with some full synthetic gear oil but not sure on what stuff to use as i've read the 6sp O2M box doesn't like other oils apparently????
oil from VW is 40quid plus VAT
anyway i have considered it but they are not so crunchy and i haven't been bothered to look into the new oil more! i might in the winter though