Our panasonic sd253 has just started doing the exact same thing. After 3 years constant use. I found that Kneading shaft unit has got tight with gunge buildup inside it, so the drive belt slips, so... no mixing! Checked price of new part �28+ ...whoah! Took shaft unit out and gave good soak in hot water, (I know you're not supposed to) it turns easily now! That amount of water won't spoil the mix, you put loads of water in anyway. If it happens again I'll take it apart by carefully popping the seal off the top, then clean the insides. Careful with that fragile (cheap 'n nasty) seal though! Hope this helps. Rob.