Make sure you don't have an override on line 28a. If the line is blank, there is nothing in the display to show that there's an override. People occasionally create an override accidentally by pressing Ctrl-D without realizing it.
I didn't ask you whether you are using Windows or a Mac. In Windows, in forms mode, right click on the space for the amount on line 28a. If one of the choices in the menu that pops up is "Cancel Override," click on that to remove the override. (If the menu option is just "Override," then there is no override.) Another way to tell if there's an override is to type an amount on the line. If the numbers that you type appear in red, there's an override. If there is no override, you won't be able to type an amount on the line. It should be similar if you're on a Mac, but sometimes there are differences in the user interface, and I'm not familiar with it.
