Rattle from clutch housing when hot ?

[Dinger1962]

Hi fellas i have recently bought an 03 fazer thou 65k miles(cheap)nice condition -runs sweet -pulls like a train.Now for the niggle-when i bought it i took it for a couple of miles and all was well or so i thought-i took it out today did a loveley 80 miles through the lakes no problems at all until i got home as bike was ticking over on my drive i could hear a distinct rattle from the clutch housing/cover i pulled the clutch lever in an the noise changed pitch/quietened somewhat--i left it for a couple of hours started the bike no noise--is it just the oil being thinner when hot or maybe something more ?(oh had no problems with clutch slipping or changing gear throughout the day )if anyone can throw some light on the subject i would be most grateful cheers Stu--