Cost Scenario shows blank status for several items

Summary

Items in Scenario show blank status, however previous cost was end dated - now getting distribution errors.

Content

Imported 2000+ items of costs to several cost scenarios - 2 problems occurred.

problem 1)  Scenarios updated successfully, however over 200 items show a status in the scenario as blank.  Inquiry on Manage Standard Costs also shows a blank status, but previous published cost now has an end date - so we are receiving distribution errors that cost does not exist.

Questions 1) Why didn't these publish, 2) Why didn't the blank status items give us an error, 3) Why did the previous standard end date when I now have no valid active cost?