unreliable server2008 connection

i'm hoping someone here can throw some light upon my problem...

We have numerous pc's, in a workgroup, all connected to a router, which acts as the DHCP server and the gateway to the internet.
We had an occasional server2003 added to the LAN for web developers to test, and browse, local websites.
(by typing http://projAA.comp.hq/ or http://projBB.comp.hq).

This all worked well by assigning to the PC's...
DNS1=192.168.5.55 (the development server)
DNS2=192.168.5.1 (the router).

This allowed everyone to always have access the internet,
and they could access the dev websites if and when the dev server was available (plugged in).

we now have a Server2008, setup just like before. Its replaced the Server2003.
BUT
very often some (random) dev website is unavailable.

i have discovered that if the dev server is on or off everyone has internet. =ok.
if i turn on the server, and remove DNS2, everyone has all the dev websites. =ok.
But the original setup is no longer reliable: the server doesnt seem to respond fast enough all the time.
And so the pc's move on to dns2 which of course knows nothing about local dev websites.

Are we just doing this wrong?
Can we make the dev server respond quicker?
or make the pc's wait a bit longer before giving up on dns1 and trying dns2?

Any ideas appreciated. Thanks.

You might want to try looking for a answer in the Sevenfourms there will be allot more people there that can help you out.