NW 6.5 SP2

DHCP subnet
DHCP scope -

Delivered addresses x.x.x.0 and x.x.x.255 within the scope don't work.
Let's say a node gets the first available address in the DHCP-scope,
in my example
Such a node cannot login to the network.
Sometimes you get a partial login, where attach might work to some servers,
sometimes you'll get no attach at all.
The next boot/login, you'll might get partial attach to other servers, or
maybe not...
As soon as the node has another IP-address (not 0 or 255), things work ok.

Should not DHCPSRVR v 3.13 (30 april 2004) handle this?
If not, how can I "en block" exclude addresses x.x.x.0 and x.x.x.255 from
the scope?
In a big scope there will be many of them, and excuding them one by one is
rather inconveniant.

If I must do the latter, the DHCP Manager says (example):
"" is not a valid selection.
I therefore cannot add these addresses as exclutions either...

Ideas anyone?