Found the problem!! My categories where Test *, Test **, Test ***, and apparently the asterisks where messing up the code. I renamed the categories and now it seems to work...

OK, will try.

In the settings tab, for each of the four categories I put 25%. In the gradebook tab, I put the same 25% for each assignment (regardless if that assignment was worth 8 point or 10 points or whatever total).