Data in Radio Buttons not displaying in IWP?

We have a database that has multiple layouts, and multiple fields per layout. Some of these include radio buttons, often with the same value list (e.g. one particular layout has three fields with yes/no choices).

The problem is, there are some of the fields which show the correct radio button checked when viewed via IWP (correct meaning what the database itself displays), and there are other fields that don't show anything checked, even though when I look at the database, one of the radio buttons is checked.

For example, on that layout that has three yes/no fields, in FM, all three "Yes" fields are checked. In IWP, the first two don't show anything checked, the last one shows a "Yes" checked.

What is causing this behavior? How can I show all of our data via IWP?

Many thanks,

Dana