I've went another way to solve compiling it - succesfully.
Because I've met problem with compliing ocaml to obraing ocamlopt native compiler, I decided to compile unison with NATIVE option turned off.
Just like this:
# normal user
make install NATIVE=false INSTALLDIR=/opt/bin/
Remember to make sure that /opt/bin is in your $PATH, in other case, just install this into /bin.
If someone needs, I can just send compiled directory, and you can put make install, on your own :).
Feel free to ping me through wikidot "mail" system :).
(Notes about this, and other wd world related, so far, I keep here: http://wiki.grzegorz.wierzowiecki.pl/notes:2009-wd-mybook-world )
As I've wrote before, If someone need those files, ping me through wikidot's mail/message system and provide e-mail address. I will send file.
Other option is edonkey download (I try to share this file mostly during day in Europe):