Subsidiary restrictions on this record error

I keep getting the following error on an Item CSV import for several records.
The subsidiary restrictions on this record are incompatible with those defined for class: XXXX Subsidiary access on this record must be a subset of those permitted by the class. XXXX in this example substitutes for several different classes of items.
Weird thing is, the import accepted other items of the exact same classes in the upload and returned the error for only a few items.
Does anyone have an idea of where to look to see if I can resolve this issue?