I am having problems with the shutil.copy2

I am making a backup program but when I use copy2 the time of my destination file is often two seconds newer than my source file. I was immediately aware that (as in previous bugs) the decimals are always incorrect (so I always use int(os.path.getmtime(source)) but i also see that the seconds are one or two of. It happens in about 10% of the files copied.

example of my trace of the check after the copy2 call "shutil.copy2(src,trg)"
rereading the mtime gives a difference of one second where the target is 1 second newer.

23:13:50 Non Copied: d:\MyPython\archief.txt , f:\PythonBackup\d-drive\MyPython\archief.txt (1177881701 == 1177881702) N

hard to believe? I also used os.utime(trg,(t,t)) to try to correct it but it gives the same error

Anybody have the same experience... and how to solve this, just installed python 2.5.1, no help.....

Which "time" is that? Windows three timestamps, IIRC: creation,
modification, access.

Thanks for your reaction, I do not really now the answer to your 
question but I added the code to copy files in a directory (to keep it 
simple I removed the recursiveness):

import os
import shutil

sourcedir="d:\\testsourcedir"
targetdir="d:\\testtargetdir"

filelist=os.listdir(sourcedir)  
for afile in filelist:
    source=sourcedir + "\\" + afile
    if os.path.isfile(source):
        time1=os.path.getmtime(source)
        print source,time1,
        docopy=0
        target=targetdir+"\\"+afile
        if os.path.isfile(target):
            time2=os.path.getmtime(target)
            if time1>time2:
                docopy=1
        else:
            docopy=1
        if docopy==1:
            print " ....copying"
            shutil.copy2(source,target)
        else:
            print " not copied"

If I run this program twice without changing any file in the source 
directory it should not copy any files anymore (but is does 20% of the 
files it there are 100000 files). Now that I have been thinking about 
this a little the problems I see, happen on a Windows Vista Business 
machine, on my XP machine i don't seem to be able to reproduce the 
issues, maybe it is somethin in Vista.....

quite frustrating....

The "f": drive probably was a FAT32 filesystem, which has a resolution
of two seconds...