Actually, it is a clean install of 10.6 with combo-update to 10.6.2. I think the system fonts are enabled by default, aren't they?
I will check this tomorrow.
This is what I have found on Google:
http://discussions.apple.com/thread.jspa?threadID=2223915&tstart=2
Seems to be the same...
Hi,
I have created a Snow Leopard NetBoot Image on my server (10.6.2).
When I boot a client computer into the image I get a pop up window that state a font ("Helvetica.dfont") had to be restored by the system for viewing purposes.
I recreated the Image several times, with all updates...