if your banner includes backslashes, then openssh-5.1 will escape all of them. so instead of just one \, you get \\. example: http://bugs.gentoo.org/attachment.cgi?id=169798 proposed fix: http://bugs.gentoo.org/attachment.cgi?id=169911 this was noted & fixed by Michał Górny
Add to the list for 5.4
Patch has been applied and will be in 5.4. Thanks.
With the release of 5.4p1, this bug is now considered closed.