edubuntu + nfs

[Antonello Facchetti]

I set up a school lab with 15 pcs and edubuntu 7.04.

A PC exports /home via nfs to the others.

I've got a problem when a class get into the lab and all the computers 
boot practically at the same time  (typical situation): some computers 
do not get the /home dir so users can't log on.

The only solution is to boot the computers sequentially, one by one, 
waiting about 30 seconds between  each one.

I tried to mount manually in a console the /homes and it takes seconds 
(about 5-10) to have a result.

Is there any misconfiguration I my have done? (really, I just edited the 
exports file)
What should I check to speed up the process?

Antonello