sorry.. the fourth characteristic cannot be set up identically to the other three! :-)
There must be a difference. it does look like it's expecting individual resutls to be recorded which normally is an issue with control iindicators.
I would see if there are mutliple versions of the characteristic and if the correct version is in the plan. Also how old is the lot and was the plan modified or updated after it was created.
You could look at the QAMV table for these four characteristics of the specific inspection lot and compare the fields. Most of them should look similar with the obvious exceptions. See which fields are noticably different and this may give you a clue as the problem.
Craig