I have asked that question before on the sling mailing list but I guess it is more appropraite here: The current stable sling release uses jackrabbit 2.1.1 which has a bug as it does not respect sv:multiple on properties during import operation.
This bug is fixed in the latest jackrabbit release (which is available in sling trunk). However I would like to stick to the stable release of sling. So I tried some kind of workaround and connected with the latest jackrabbit cli to the existing repository (2.1.1) and imported successfully. Afterwards I continued with sling and jackrabbit 2.1.1 and so far haven't had any problems. Before doing so in production I would like to ask whether this temporary switching of jackrabbit versions on the repository can have consequences I can not easily recognize. Thanks, Markus
