openssh-2.9p1 scp to ssh-2.4 fails

[J.S.Peatfield at damtp.cam.ac.uk]

Damn finger trouble... (must learn to cut/paste...)

Am I missing something obvious or does the scp in openssh not
interoperate with the scp in ssh-2.4?  I don't have any ssh-2.4
systems but a user here trying to fetch a file from a site which uses
it (and doesn't have scp1 gets):

$ scp -o 'protocol 2' -v foobar at somesite.com:tf19.dat .
Executing: program /usr/bin/ssh host somesite.com, user foobar, command scp -v -f tf19.dat
foobar at somesite.com's password: 
scp: warning: Executing scp1 compatibility.
scp: FATAL: Executing ssh1 in compatibility mode failed (Check that scp1
is in your PATH).

I assume that the scp warning is comming from the far end.  Turning up
debugging shows that ssh protocol 2 is correctly being used, but for
some reason the remote scp tries to run scp1 (which isn't there).
Does ssh-2.4 use a different form of scp to that used by ssh1 and
openssh?

Is there an obvious fix (other than trying to get the remote site to
update to openssh)?

Is the scp protocol used in ssh-2.4 documented?  Could we add support
for it in openssh?

 -- Jon