No network after LVS kernel install

[Keith Edmunds <keith@xxxxxxxxxxxxxxx>]

I'm trying to set up an Ultra Monkey cluster. I'm using Debian Woody; I've 
installed the UM3 version of initrd-tools plus the kernel and headers; 
I've edited lilo.conf and run lilo, edited /etc/modules and rebooted. 
The LVS kernel has come up, the network module (8139too) has loaded, and 
both mii-tool and ifconfig show that the network is up. "route -n" shows 
that the routes are correctly configured. However, I cannot access the 
network at all. When logged into the server, ssh to the system's own
address(10.100.100.100) works fine, but ping to 10.100.100.101 fails.
Rebooting to the old kernel solves the problem.

I'm not really sure what to check next; any pointers appreciated.

Thanks,
Keith