There is a validation error when you grade a forum, the grade is correctly stored but there is a warning in the validation.
It says the entered grade is higher than the max score, but is not. Seems a problem with the decimal separator.
Steps to reproduce it:
1-Create a gradebook item (MAX 1 point)
2-Create a forum assigned to the gradebook item.
3-Grade the forum assigning 0.3.
4-The validator says the score its bigger.
5-If you save it, will be stored correctly.
See atachment for more information.