strange sshd failure at startup

I'm running openssh-3.9p1 on linux mandrake 10.2, with a self-compiled
kernel 2.6.11. Since a few days, I'm experimenting strange failure to
launch sshd at boot, while manually launching it is OK.

Even with maximum debug value (DEBUG3) in sshd_config, all I have in
auth.log is
Oct 20 11:00:02 ryu sshd[5402]: debug1: Bind to port 22 on 0.0.0.0.
Oct 20 11:00:02 ryu sshd[5402]: Server listening on 0.0.0.0 port 22.
Oct 20 11:00:02 ryu sshd[5402]: socket: Address family not supported by
protocol
Oct 20 11:00:33 ryu sshd[5402]: Received signal 15; terminating.

The 3 line should be caused by the absence of ipv6 support in my kernel.

The return value from sshd in init script is 11, meaning "ressource
temporary not available" from errno.h, but I can't find which ressource
exactly.

sshd worked perfectly before. The only change we had recently was
introducing RSBAC support, but it is disabled in current kernel
(rsbac=0), and I tested with the same result with a previous kernel. The
problem initially occured after I changed the boot sequence to mount an
external USB disk before LVM activation, but reverting the changes
(modprobing usb-storage earlier) didn't change anything.

All other services start correctly.

Any suggestion ?

-- 
You will always get the greatest recognition for the job you least like
                -- Murphy's Laws on Work n°27