991 Sunroof Operation

[Al's 991]

The sunroof on my 991 works ok apart from the noise it makes when opening and closing. Has been back twice to OPC, first time greased and second time a lot more grease. In fact so much grease when roof was open the grease came off onto the back window. Roof still makes the noise. Before I go back again for a fix I was just wondering if anyone else has this issue with their 991 sunroof.