5ht gear vibration

I wanted to know if anyone else who has an S60 R has experienced vibration in 5th gear with the 6-speed? I have it in my car and the dealer told me it was a "problem" with 2004 S60 R 6-speeds. He also said they had a fix for it, which they performed and it did not work. Does anyone know of this and how I can fix it?

Thanks