[Andrew]

Ward, in OmniOutliner if you have multiple columns and there is data in any of the columns, then hitting delete at the beginning of the first column will move to the previous row without deleting the initial row. Is it possible that this is what you're seeing?

If, on the other hand, all columns are empty, then the delete key will delete the current row. I just tested again in the 3.7.1 beta and confirmed that it's working as expected, so I'm not sure why you would be getting a different behavior. Could you try it in a different user account to see if it's somehow related to your specific account? (If it is, it might conceivably be related to preferences, so you might try moving them aside.)