I often try to cram so much data onto my screen that some of the columns are only just wide enough for the data. Under these circumstances, the column name is frequently wider than the column and is displayed as Di.... or something similar.
It would be helpful if the full column name was displayed as a pop-up help when the mouse pointer is hovered over the column header - just as the tab header is displayed when the mouse is hovered over a tab. My tabs bar is set to Horizontal (Caption Bar) in case it makes any difference.