[CentOS] Unable to use SSH password-less logins

I am trying to ssh from my Windows/Cygwin xterm window into my CentOS52 
servers w/o using passwords but my keys seem like they're being ignored.  I 
created the key in cygwin using:

$ ssh-keygen -t dsa -f id_dsa

And copied id_dsa.pub over to centos:~/.ssh/authorized_keys

Ideas?

tia,

 - Joe