Xen 3.3.2 (pkgsrc2010Q1) + netbsd 5.1_RC2 + radeondrm = crash?!

[erinlalouve%free.fr@localhost]

hi everyone,

today I tried to have Xvideo on my computer with Xen and NetBSD-5.1_RC2 (amd64) 
as dom0.

I have a radeon HD4350 which is perfectly regognized with radeondrm:
dmesg:
radeondrm0 at vga0: ATI Radeon HD 4350
radeondrm0: Initialized radeon 1.29.0 20080613

but when I try to launch X, system crash. I found on the ml that someone 
succeeded to have Xv by setting NoAccel to "True" in Xorg.conf 
(http://old.nabble.com/Xen-and-DRM-td27270432.html).
It also seems that the crash did not generate coredumps nor logs. did I miss 
something?