Gradebook

Hello!
I needed to grade the assignments in a course with a 0.25 scale: from 0 to 4 points via 0.25, 0.5, 0.75 etc. for each assignment
So I've created a scale with corresponding values.
When I look at the gradebook, it says that the maximum value for each assignment is 17.00 (?? I guess it just counts the number of scale marks), I failed to find the way to tell the gradebook that 4 is really 4, not 17.
Any help would be highly appreciated.

To summarize, I've got 2 problems:
1) how to grade with a 0.25 scale (w/o creating a custom scale)
2) if the custom scale was created, how to use it in a gradebook, the scale is numeric and I just need a sum of all grades I actually entered.

UPD: The grades in the "sum total" are shown with comma as delimeter, e.g., 13,00 and the dot is used in the scale, e.g. 2.25. May this be a source of the problem? If so, how can I change commas in sumtotal to be dots?