Ok, thanks, I already contacted them and got reply.

2009/12/18 Ng Oon-Ee <ngoonee@gmail.com>
On Thu, 2009-12-17 at 23:10 +0100, Martin Horn wrote:


> I installed a 2.6.31 kernel via apt-get on my 64studio machine but
> booting the kernel doesn't work ("this kernel requires the following
> features not present on your cpu: pae"). If anybody can help with this
> - thanks a lot!

Basically the kernel was compiled with PAE support and your cpu doesn't
support it, I believe. Didn't even know that was an issue, but you
should contact 64studio and ask about this, they probably have a
separate kernel without PAE compiled in.