Strange problem with amongst other live.com and login.facebook.com

[Martin Rise Christensen]

I have, one wan line, connected to my firewall. On the inside of the firewall, I have multiple lan. One lan for the adminstration that works just fine - another lan for the studens with captive portal enabled.

My administration network, have no problem connecting to anything, but my students have trouble accessing  for instance facebook.com or login.live.com - and they are on the opt1. network. The firewall rules are exactly the same etc. for some strange reasons, it seems to me that the nat does not work, when comming from 10.0.1.0 network instead of the administration network that has ip range 192.168.1.0.

Any suggestiens?

Kind regards,

Martin