Clutch - diffiiculty getting into 1st & reverse

[auberrow]

I bought my new shape AClass A160 CDI in December 2005 as a driving instructor training car. After 6 months I had trouble engaging 1st and reverse. I was told that MB had flagged up the problem and that the clutch was sticking on the spline. The transmission was dropped out, the spline greased and replaced - two days work. Three months later the same problem has occurred again; has any one experienced the same problem and is it likely to reoccurr on a regular basis?