My 998 is about 18 months old now, Ive had it for 5 of those months. It had 760 miles on it when I picked it up, and now has 4060, so it was somewhat overdue a tyre change. Got the tyres changed yesterday. Obviously the rear wheel had never been removed from the bike and had become fairly well attached to the spindle with what looked like a dried out chalky white material (presumably some kind of grease originally?). We got the wheel off with some gentle rocking and friendly persuasion... So, if you are running a low mileage bike and have never had the wheels off, I would take it somewhere to get them to undo it (if you don't have the facilities at home) and whip the rear wheel off and get the spindle copaslipped or whatever before it gets well and truly stuck. It probably also applies to some of the other components on the bike, but I haven't got that far yet.
cheers, Ben ps - was going to post this in the DSC messages as a post for all to see - thoughts?