Excel doesnt like slashes

I noticed something weird when I was recently using Excel.  I was typing in data into a spreadsheet.  One of the columns contained Unix paths.  I have two monitors: one with Excel and one with Putty.  I was looking at the Putty window while typing into the Excel window.  After typing a block of data in, I took a look at Excel and it was all messed up.  There were 4 sub-windows that all showed the same spreadsheet.  Apparently, the front slash is a special key.  Most of the time, you can select a cell and just start typing away.  I learned a valuable lesson: that feature (typing into the cell and not the value input) is highly dependent on your data.  All my rows were empty!  Doh!