I have this problem: arp table filling up

But I am quite sure that I cannot blame Kaspersky.

Scenarie:

• a user plugs his computer in.
• He waits and waits but are getting no IP by DHCP.
• Then he is told there is an IP conflict...
• He end up assigning himself a static IP to access the net

In the ARP table of the router I see:

192.168.24.144  00:16:41:42:3c:9e   Lenovo  LAN
192.168.24.145  00:16:41:42:3c:9e   Lenovo  LAN
192.168.24.181  00:16:41:42:3c:9e   Lenovo  LAN
192.168.24.150  00:16:41:42:3c:9e   Lenovo  LAN
192.168.24.151  00:16:41:42:3c:9e   Lenovo  LAN
192.168.24.152  00:16:41:42:3c:9e   Lenovo  LAN
192.168.24.156  00:16:41:42:3c:9e   Lenovo  LAN
192.168.24.157  00:16:41:42:3c:9e   Lenovo  LAN
192.168.24.159  00:16:41:42:3c:9e   Lenovo  LAN
192.168.24.160  00:16:41:42:3c:9e   Lenovo  LAN
192.168.24.130  00:16:41:42:3c:9e   Lenovo  LAN
192.168.24.132  00:16:41:42:3c:9e   Lenovo  LAN
192.168.24.164  00:16:41:42:3c:9e   Lenovo  LAN
192.168.24.137  00:16:41:42:3c:9e   Lenovo  LAN
192.168.24.140  00:16:41:42:3c:9e   Lenovo  LAN
192.168.24.206  00:16:41:42:3c:9e   Lenovo  LAN

The last .206 is the static address he gave himself.

Several users descripe the exact same problem. It started after removing some filters in the switches, så all users are on a LAN and can see each other. Before, when filters blocked access to each others comptuers no one reported this kind of behavior.

Any idéeas?