Sharing a List Managed Worksheet In Excel 2004 For Mac Os X - Unable to Delete Rows



I have been managing a shared jobs worksheet with Excel 2004 for Macintosh with 6 other people. I recently converted that worksheet into a list using the list manager. Ever since, I and everybody else have been unable to delete rows within that list--the option is grayed out under the pop-up menu. Rows can still be added, information within that list can still be edited, and cleared, but the row itself cannot be removed. If I unshare the list, I can delete a row, but while it's shared, no go. Can anyone tell me why/offer a solution?

Thanks a million,