We have discovered an ingenious new problem plaguing the CA scheduling 
spreadsheet.  I do not know how this happened, but here is the symptom.  You 
open a spreadsheet and you see a little version number behind the name like 1 
or 2.  For example:

ca1212.xls:1
ca1212.xls:2

Sometimes you may see a file's name several times under Window as if you 
somehow have several copies of the same spreadsheet open.  This apparently 
results from selecting Window > New Window.  Never, ever select New Window!  
I repeat: NEVER, EVER SELECT NEW WINDOW!  Once a worksheet has this version 
number it is "contaminated" and all sorts of other problems appear.  I'm sure 
you have noticed new errors popping up when you open or close one of these 
files.

I am going to create a new worksheet for the 13th from an older file that 
does not have one of these version numbers.  And we will hope this doesn't 
happen again.  Please be careful with this.  It sounds trivial but can in 
fact really screw things up.