Auth timeout using SSH


I'm admin'ing an OSX educational network and ran into a slight problem. A user attempting to mount a network drive is unable to. When she tries, it hangs and on the server in console the following errors are given:

fatal: Timout before authentication for <ip>
and sometimes:
error: ssh_msg_recv: read: header -1

I looked this up elsewhere and some BSD boards say to edit /etc/hosts.allow but I cannot locate this on the server. Any suggestions?