Often it's desirable to make a master slide based on an existing slide. Without crazy workarounds (e.g. renaming a master slide, saving the document, then copying the a slide from the saved document back into the original document) this is not currently possible. This is technically an enhancement, but it looks like a bug, and it's been annoying users for years (I found mailing list messages back to 2005 about this problem when I looked!).
[This is an automated message.] This bug was filed before the changes to Bugzilla on 2011-10-16. Thus it started right out as NEW without ever being explicitly confirmed. The bug is changed to state NEEDINFO for this reason. To move this bug from NEEDINFO back to NEW please check if the bug still persists with the 3.5.0 beta1 or beta2 prereleases. Details on how to test the 3.5.0 beta1 can be found at: http://wiki.documentfoundation.org/QA/BugHunting_Session_3.5.0.-1 more detail on this bulk operation: http://nabble.documentfoundation.org/RFC-Operation-Spamzilla-tp3607474p3607474.html
Confirmed in 3.5.0beta1. Changing back to NEW.
Btw. this is the same as the high rated report https://issues.apache.org/ooo/show_bug.cgi?id=70587. Best workaround at http://www.oooforum.org/forum/viewtopic.phtml?t=27162: 1) Save a copy of the presentation 2) Rename the Master Slide 3) Copy a slide in from the presentation copy
*** This bug has been marked as a duplicate of bug 45617 ***