Bug#495917: Fixed in upstream
we have the same problem with our Juniper Firewalls. I have created a
case do get the patch from Juniper, too.
Another workaround is to patch the openssh-client. In the CVS-Upstream
of OpenSSH 5.1 this has been already fixed about 2 months ago:
Perhaps this patch should be included also in the debian package.
Mit freundlichen Gruessen / Kind regards,