I just got fooled. I was looking at file dates in a directory list and saw this:

file1.txt 1/15/2006
file2.txt 1/15/2006
file3.txt 1/15/2006
file4.txt 11/5/2006
file5.txt 1/15/2006
file6.txt 1/15/2006

I couldn't understand why file4 hadn't changed in ten months. Then I looked more closely.