BOM in drawings

I am adding a BOM to a drawing of an assembly. In that BOM, I have Item No, Description, Qty, Part No and finally a column for the Issue. The information is linked to the custom properties of each part. The only problem is with the ISSUE column. I cannot select a particular revision level for each part. If I select Revision level 3 for instance for one part, custom prop. rev_level_3 will populate right across all the cells in the ISSUE column: if a part hasn't been up-issued to that rev. level, the cell is left blank. I have to double click and re-enter the rev level manually. The cell properties dialog box only controls the text justification & font, not the actual content of the cell. Am I missing something? Thanks.

I am adding a BOM to a drawing of an assembly. In that BOM, I have Item No, Description, Qty, Part No and finally a column for the Issue. The information is linked to the custom properties of each part. The only problem is with the ISSUE column. I cannot select a particular revision level for each part. If I select Revision level 3 for instance for one part, custom prop. rev_level_3 will populate right across all the cells in the ISSUE column: if a part hasn't been up-issued to that rev. level, the cell is left blank. I have to double click and re-enter the rev level manually. The cell properties dialog box only controls the text justification & font, not the actual content of the cell. Am I missing something? Thanks.