[nsp] strange dhcp behavior

[Roger]

I've setup a dhcp server on a 1605 running c1600-y-mz.122-23.bin

The dhcp srever statement is as follows.

ip dhcp pool 8th_floor
   network 192.168.20.0 255.255.255.0
   dns-server 209.94.40.2 209.94.48.2
   domain-name rockriver.net
   default-router 192.168.20.254
   option 66 ip 192.168.20.218
   option 150 ip 192.168.20.218

The problem is some hosts, xp machines and Cisco 7940 phone are getting 
very strange broadcast addresses

ip info on a 7940 is as follows

ip 192.168.20.137
mask 240.255.255.0 <-not a typo
gateway 192.168.20.254

I've also got xp machines w/ the same strange subnet mask..

Anyone have ideas as why this is happening..  The hosts w/ this strange 
subnet mask can still connect to the outside world..  I've rebooted the 
router - still same strange ips.