I'm having troubles with su.  I don't seem able to su to any account
unless I login as root.  I can't even su into the account I'm already
logged into.  When I do "su someusername" it prompts me for a password and
when I give it the correct password I get a "Sorry".  Su-ing from root to
another account works peachy.  It sounds like a permission problem to me.
Here is the permissions set for su and passwd(which I assume su reads):

 -r-xr-xr-x  1 root  wheel  16384 Jan 21 17:40 su
 -rw-r--r--  1 root  wheel  728 Feb 10 11:48 passwd

So it looks like I should be able to execute su and read the passwd file.
Are there any other files I should be looking at?  

---
Brian Carroll
bwc8@cornell.edu