ssh forwarding question

[Pollywog]

I installed tightvnc on FreeBSD 6.2 and I start the vncserver on that machine.
Thereafter, I can do vnc via ssh to that vncserver from my kubuntu desktop 
with something like this (hostname is the only thing changed to protect the 
innocent):

ssh -L 15901:localhost:5901 -N -f -l pollywog myhost.example.com

However, when I attempt to connect to that vncserver from my laptop running 
FreeBSD 7 I always get this:

bind: Can't assign requested address
channel_setup_fwd_listener: cannot listen to port: 15901
Could not request local forwarding.


Is the "bind" referring to the nameserver BIND?

BTW I am able to connect to the vncserver from the laptop, just not via ssh.