Why can't I sort a 2003 file in 2007? 2007 freezes.
 

Excel 2007 freezes when I try to sort or filter an Excel 2003 file. The 2003
file is fine until I try to sort and then it gets stuck and I have to use
Task Manager to shut down Excel. The original file is 1,800 lines and it
gets stuck even when I cut it down to 200 lines. Some of the columns are
hidden--would that account for the problem?