ethernet bridge failing

I have a frustrating problem with my ethernet bridge.

I have set up a ethernet bridge with eth1 and tap0-5 for OpenVPN tunnels.

The server boots fine, and on startup has a touting table of

[root@k2h002 root]# netstat -nr
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
217.45.214.32 0.0.0.0 255.255.255.248 U 0 0 0 eth0
10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth2
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 br0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 217.45.214.38 0.0.0.0 UG 0 0 0 eth0



After about three of four hours, the bridge fails, and the routing table
drops it's route to br0, and two routes to eth1 appear, thus messing up
routing. I am using kernel 2.4.21-0.28mdksecure and Intel Etherexpress
NIC's, bridge-utils-0.9.6-1mdk


I will try upgrading to a newer kernel tomorrow, but has anybody got any
ideas why this is happening ?

thanks