problem with xen kernel on amd64

[edu gargiulo <egargiulo+lists@gmail.com>]

I have installed xen-linux-system-2.6.26-1-xen-amd64 on a fresh debian
testing. After that, I can't start X. The X log says

xf86MapVidMem: Could not mmap framebuffer (0xfbfd0000,0x4000) (Invalid argument)

there is a problem with this kernel version on amd64. I've used the
same kernel version on the same PC with i386 without problems.

How can I fix this? Could I compile the
linux-kernel-2.6-26-1-xen-amd64 and don't include framebuffer on the
kernel? How?

thanks in advance and sorry for my english,

PS: I have tried putting Options "UseFBDev" "false" on xorg.conf
Device section without success.

--
edu