openssh login issue

1.server: openssh 3.9p1 + fedora core 3
2.error from server authpriv: openpty: No such file or directory
session_pty_req: session 0 alloc failed
error from putty: server refused to allocate pty
3. symptom from Linux ssh client by command 'ssh servername -v':
no error, hanging to wait for command prompt coming out

4. solution:
go to /dev/pts/, check any file is there, e.g. 0 is there
fuser 0
kill -9 the process number
try again.