The AMD64 version is the 64 bits for AMD AND INTEL...
Kernel 2.6.32-25 generic is stable. Right now I'm using Kernel 2.6.35 and
2.6.36 git 8 is in the oven now. So you're using at least 10 versions behind the
current kernel. It is a quite tested kernel. I would rather look drivers
version for your material or configuration parameters. More chances this side.