Indeed, we use it on 4 others Joomla websites, without any problems.
Maybe it could help :
In Ajaxian Index Generation mode we have : "Core Index generation task failed - getIndexBegin Start Process is already running (tmp_object_relations detected) - Manually drop the table or "Recreate Views" from "Promoted Entries Configuration"."
So, manually drop the table could fix the issue, but which one ?
I think this is related to my recent post "My SobiPro Entries for Jomsocial". Upon doing Entries Explorer for XTDir My SobiPro Entries the initial Sobipro Section 1 is successfully indexed. However new Sections that I have created in Sobipro are not indexed although the section itself is visible in Entries Explorer.
Its almost as if creating a new Section in Sobipro has a flag which prevents it being indexed by another application. Maybe reloading the section is a way of overcoming this.
I'm not sure if the Jomsocial issue is due to a problem with Jomsocial, or the XTDir My SobiPro Entries plugin or Sobipro, but increasingly I think that Sobipro new section is blocking indexing.