Idea/bug-report:
If you have a multicolumn listbox with column headers and you want to delete one of the columns you can right-click on the column and select delete column, but if there are no items in that column LabVIEW will not actually do anything(!):
This also applies to empty rows with headers. This is non-intuitive and makes it cumbersome to remove a header and keep the width/height of the ones you want to keep...
I've created Bug 2841623 for this issue.