Static local ip address keeps changing

[hough]

All,
on my local network, the static ip addresses keep changing on my windows machines.i set the ip address 192.168.0.13 255.255.255.0 192.168.0.1(pf sense box)

after 10 seconds the ip address is changing to 192.168.0.4.

ipconfig shows 192.168.0.4 (alternate)

what would cause a static ip address to be added to an existing connection.

i do have dhcp setup on my pfsense box but the dhcp addresses start at 192.168.0.80

i am stumped.