The oil won't make it jump. Just follow the manual with regards to oil change intervals.
Jumps may be caused by a glazed clutch. What they do is sand the surface of the clutch to remove glaze.
I had jumps before but since I don't have the time to dismantle things, I just ignored it and rode. No more jumps now. Maybe a few hard accelerations may cure some small jumps.
What!! Are you saying I could of left it and would of been fine? Oh well, you learn new things everyday lol. You know whats funny, looking at the belt again, it seems like nothing is wrong with it eh. Should I post a pic of it here? Oh well, what's done is done. At least I can leave it the next time it happens again.
Too easy, thanks for the useful info again guys.
CHEERS