I have just installed my very first DSfW server and I think I may have
made some incorrect assumptions about DNS for DSfW and our existing DNS

Our main DNS is running on two NetWare 6.5sp8 services with foo.com

We installed DSfW from OES11sp1 and it set up its of foo.com.
So now if we look at the DNSDHCP console we have two foo.com entries.
The DSfW server is pointing to its own hosted DNS, and all of my users
are pointed at the main DNS servers.
At this point everything is happy.

In this state, obviously any machine that I join to the DSfW server
will need its DNS set to the DSfW server - and that machine won't pick
up any of the DNS entries from my main DNS servers.

So I set up DNS forwarding on my DSfW server to my main DNS servers.
This seemed to work ok for a day and then stopped working. I did note
that DNS has stopped on the DSfW server - not sure why. I did a
xadctnrl reload and everything looked ok but DNS forwarding would no
longer work.

I've verified in the DNSDHCP console that the DSfW zone of foo.com has
the Forwarding List set to my two existing DNS servers.
I've tried restarting the server on the off chance. But no luck.

The questions are, should this work or have I made a rookie mistake?
Any ideas how to fix this?