What am I doing wrong with my rice cooker?
Does your rice cooker have a scale up the inside of the bowl?

With mine, you add a number of scoops of rice, then fill with water up to the correct number on the side of the bowl. Maybe it is just that the manual is badly worded, and this isn't clear?

It's a long shot, I know, but just thought I'd mention it in case you hadn't noticed :)