I have the same problem, a CBA Columns.Autofit never returns, stops dead in its tracks. I've tried 1 dozen combinations of Range.AutoFit (and with the EntireColumn in the Range, too). This code ran literally >10,000 times, then stopped working, so it's an Excel problem, maybe with the VBA compiler. I only made code changes to a single module devoted to a completely different area of my program. I've reorganized my code to see if the bug was squashed, but it wasn't. any ideas?