I have a similar problem with my People S200. I took off the clutch bell and also found grease inside it. Not sure where this came from. I cleaned up the grease in the clutch bell, and cleaned both the bell and shoes with solvent. After a light sanding of the pads, I put it back together.
The rough grabbing is still there.
One thing I noticed when I had the bell off is that the shoes didn't move very freely - their motion was damped. The springs pulled the shoes in _slowly_. I believe that the problem is that the lubricant on the clutch shoe pivots has dried and turned gummy. Next time I'll take the clutch apart fully, and clean and lube the shoe pivots.
Cortez has posted that holding the brakes and giving some gas helps. In mine it does, but only temporarily. I believe that the brakes+gas heats up the clutch, which makes softens the lubricant. I notice the problem more on cold days.
Has anyone else had this problem? If so, what was the fix?
