I have noticed something strange when it comes to SIP addresses in Lync 2013. In Office365 sip addresses with special caraters are just forbidden. Like /()# and more.
But in Lync 2013 they are allowed, but I would not use it because it will make the Lync 2013 environment to go down.
Do not use / or () in sipaddress or in displayname even it's allowed.
I hope that Microsoft in some CU will come with an update that it disallowed to use these letters, because in worst case you might have to reinstall you entire Lync 2013 deployment.