I upgraded my Office Communicator 2007 to R2 last week, and my custom presence stopped working. Turns out R2 will assume default security for transport, which is set to High, and then requires your custom presence XML file to be an HTTPS URL. Even if you set your registry entry to be an https path it still won’t work. The link to the articles that did help can be found here:
Basically, you just need to create a .reg file and load it with this:
Windows Registry Editor Version 5.00
“CustomStateURL”=”C:Program FilesMicrosoft Office CommunicatorPresence.xml”
Just replace the path in CustomStateURL with the path to your local XML file with custom presence info, run the .reg file and restart Communicator. Enjoy!