Apologies if this has been discussed already. I found a thread regarding ADD_SPELL "no slots" and SPIN spells here
http://forums.pocketplane.net/index.php?topic=29433.0 but I am reporting a different issue.
More details here:
http://www.shsforums.net/topic/56752-the-official-bwp-fixpack-thread/?p=586876Briefly, unless I've missed something else in the Divine Remix code, it seems that calling ADD_SPELL to modify a pre-existing IDS entry causes that entry to be deleted if the "no slots remain" error occurs.
Edit: also, I would like to second the request from the other thread for the "no slots remain" error to at least result in the component being INSTALLED WITH WARNINGS instead of SUCCESSFULLY INSTALLED.