Sorted it myself in the end.
Never reallt dealt with LDAP before, so when I ran dsquery to get the info I needed for the LDAP settings, I`d also copied the CN=USERS part.
I was staring at the settings and wondered if that meant it was only searching within Users in the AD, so I removed it, the test was still succesfull, so then I re-ran the Sync, which was also successfull but now I can see computers and my AD structure.
Frank.