Passwd -f locks out login

hello;

I have inherited a SunOS sjcorpftp 5.10 Generic_118855-36 i86pc i386 i86pc

whenever someone needs a new password, I change it via

"passwd username"  

then

"passwd -f username"  so they can change their password

on my only sun sparc 5.9 you can "accessed denied" when you login as username

anyone seen this before

thanks much