rsync sending all files

[Hui Nee Chin]

Hello there,

   I am a relatively new user of Unix, and I came across this mailing 
list from http://samba.anu.edu.au/rsync/. I'm in a situation where I 
needed to use rsync to sync files from my machine to a remote server. As 
I understand it, rsync only copies files the differences, which means 
logically, if I were to run the exact same rsync commands one after 
another, I should see that no files are transferred the 2nd time, 
correct? However, when I run rsync on my machine, ALL files are copied 
over to the remote machine no matter how many times I run rsync 
consecutively. I've been reading up on rsync on the net and I couldn't 
seem to find any explanations to this, except the bit about the -u 
option, which I was able to use to make rsync work as I wanted it 
to--only copy the files that were changed and leave the others alone. 
But as I read on, it seems to me that rsync is supposed to do that 
anyway even without the -u option, right? This is driving me nuts, so if 
anyone can clue me in on this, that would be great.

Thank you people!

regards,
Hui Nee