Excel has turned my circles into ovals.
 

I've done some searching and can see that when printing, perfect
circles can turn into ovals, but that's not my problem. I created
several workbooks, all similar, with lots of perfect circles in them,
saved them and come back to them later and they have all turned into
oval shapes.

Any idea what I might have done to distort them so, or if some bizarre
function in Excel has caused this?

I am using version 2000 on one computer and 2002 on another, but as far
as I can see, the changes all happened on the 2000 computer that they
were created on, on files that had been opened only on that machine as
well some opened on the other.

Lee