zsh: completion over nsf file systems

[virgil adumitroaie <va@xxxxxxxxx>]

i have started using zsh recently. all is wonderful (i am very happy
about 
xterm title bars, works wonders for gnome users) except one difference 
between zsh and bash which i cannot eliminate. 
file name completion works under bash even for nsf file systems but not
under zsh.
for example, issuing

ls /hosts/other_machine/exported_directory/<TAB>

under bash I would be able to see the subdirectories, but under zsh not.
is this something that can be configured with compctl and if yes, how?  

thank you,

virgil