This Topic is to clear any confusion as to what OpenXenManager manages. By default in Debian you can install xen. The OpenXenManager only works with "xenServer" which is not part of Debian, but needs to be downloaded from Citrix.com
Any settings that enable rpc protocol or change port in are not supported by openxenmanage:
If there is a way for openxenmanage to work with default xen in Debian please post, otherwise you will nee to find different gui to manage xen available in debian.