During 2 implementations of Sametime 9 I recognized that if you modify the default path for the document conversion directory from c:\temp\docshare to any other value, the modified directory is deleted during the start of the Meeting Server and then no more documents can be uploaded to any meeting room.
You can create the configured directory manually and then the upload is working fine again, but after a new start of the Meeting Server the directory is removed again. Only the default directory stays after a server restart !!!
PMR with the wish of either disabling the possibility to change this setting or changing the code to accept another directory already opened.