Need help bisecting 2 kernels

[rihad]

Hi, folks. I've been experiencing a Kubuntu bootup issue of kernel not 
initializing Device Mapper properly (see 
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/880646 for 
details). Now I need to bisect 2 kernel versions to determine which 
commit started triggering this bug, and since I'm in no way a kernel dev 
I'm having a hard time with that. Can you write or point me to a simple 
how-to on the matter? I've tried this one: 
https://wiki.ubuntu.com/Kernel/KernelBisection but I just can't get it 
right.
Specifically I need to bisect these kernel versions:
good: 2.6.37-11.25
bad: 2.6.37-12.26

"bad" is where things started being wrong.

TIA!