Ubuntu Servers :: Dropping Network Connection And Other Errors

I set up the web/backup server for our department and I'm having some major issues. Firstly, the server seems to be dropping the network connection periodically. I checked all of the logs and it appeared to be an IP6 issue as the only message that seemed to correlate with it was "eth0: no IPv6 routers present" in syslog. I added "ipv6.disable=1" to my boot options in menu.lst and this seemed to take care of the problem. However, I woke up this morning and the server was back down.

This didn't seem to take care of the problem. It seems to occur when my automatic backup scripts go through. I have several BASH backup scripts that use rysnc over SSH to backup several computers to the server and the server to my desktop at home. I was able to trigger the problem a couple of times running the backup script this morning. Now, I'm getting the following error when running the script, instead of losing the network connection:

Code:
Sep 11 10:22:40 chemistry kernel: [ 396.892699] BUG: unable to handle kernel NULL pointer dereference at 0000000000000118
Sep 11 10:22:40 chemistry kernel: [ 396.892715] IP: [<ffffffff811426c0>] __dentry_open+0x240/0x370
Sep 11 10:22:40 chemistry kernel: [ 396.892728] PGD 1113d5067 PUD 11458c067 PMD 0
Sep 11 10:22:40 chemistry kernel: [ 396.892737] Oops: 0000 [#1] SMP
Sep 11 10:22:40 chemistry kernel: [ 396.892743] last sysfs file: /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor
Sep 11 10:22:40 chemistry kernel: [ 396.892750] CPU 1 .....

I tried booting with a previous kernel to see if that was the problem and I'm still getting this error. I've searched through all of the logs that I could think of to try to track down any software based problems and I just don't see anything. In the past, whenever I've run into such serious with a Linux box that popped up out of nowhere, it's always been a hardware failure. I've currently disabled all of the backup scripts and I'm going to see if it lasts through the weekend.