I took a look in /var/log/debug and found this :

Sep 29 18:21:20 taint kernel: CPU: After generic, caps: 0183f9ff c1c7f9ff 0$
Sep 29 18:21:20 taint kernel: CPU: Common caps: 0183f9ff c1c7f9ff 0$
Sep 29 18:21:20 taint kernel: eth0: Identified 8139 chip type 'RTL-8139C'
Sep 29 18:34:16 taint kernel: CPU: After generic, caps: 0183f9ff c1c7f9ff 0$
Sep 29 18:34:16 taint kernel: CPU: Common caps: 0183f9ff c1c7f9ff 0$
Sep 29 18:34:16 taint kernel: eth0: Identified 8139 chip type 'RTL-8139C'
Sep 29 20:32:55 taint kernel: ISO 9660 Extensions: Microsoft Joliet Level 3
Sep 29 20:32:56 taint kernel: ISOFS: changing to secondary root
Sep 29 23:33:25 taint kernel: ISO 9660 Extensions: RRIP_1991A
Oct 1 05:05:58 taint kernel: CPU: After generic, caps: 0183f9ff c1c7f9ff 0$
Oct 1 05:05:58 taint kernel: CPU: Common caps: 0183f9ff c1c7f9ff 0$
Oct 1 05:05:58 taint kernel: eth0: Identified 8139 chip type 'RTL-8139C'

I have identified the problem to be with faulty leaking caps on the motherboard.

After 6 years ?

Edit: I see that you've edited the first message today. A new way of thread resurrection .

Although this is an ancient post by any standards I hope you don't think the kernel message relates to capacitor leakage on your motherboard, This message is passed from the kernel cpu detection subroutine in common.c in your kernel source tree.

That function is true yes but the leaking capacitors cause any number of weird things happen to any operating system, usually kernel based since it's such at such a low level, I see what you were referring to the "caps" in there which has nothing to do with what I was referring too. After the motherboard was switched out with an identical one the system runs stable again.