error in rsync protocol data stream (code 12) at io.c(139)

[Victor J. Hernandez Gomez]

When trying to connect to a rsync server (sparc.solaris.2.6) from a 
linux machine (redhat 6.2).

# rsync machine.upo.es
ksh: rsync:  not found
rsync: connection unexpectedly closed (0 bytes read so far)
rsync error: error in rsync protocol data stream (code 12) at io.c(139)

Both machines have 2.5.1 version of rsync code, compiled from scratch. 
rsh is working
properly when rsync is not in scene.

Thank you in advance for your help,
--
Víctor Hernández
Centro de Informática y Comunicaciones
Universidad Pablo de Olavide, de Sevilla