There’s a problem with the slapcat dump on Debian Lenny (I don’t know about newer versions of Debian) : characters after the 80th column goes to a new line, causing errors in slapadd during a restore .
For exemple :
[...]nal-domain,dc= fr modifyTimestamp: 20100928100440Z
In fact, it’s not a problem, but a ‘design’ of the LDAP LDIF RFC (RFC 2849).
Here is a workaround (you have to redo a backup of course), but you can do it in any other scripting language:
slapcat .... | perl -0pe 's/\n //g'> backup.ldif