I recently (week of Nov. 10th, 2013) downloaded the latest version of LibreOffice (Span. version) for Windows 7 and Windows 8 operating systems. In both downloads for these two computers, I was not able to create new themes in the gallery with differing images. I would create one theme, and add images. When I would then create a second theme and add different images, Lo and Behold - the second new theme’s images would then appear duplicated in the first theme’s spot. Additional new themes would produce the same outcome, giving me the latest images which were added in all the new themes created. The previous images which were added in the previous themes would disappear from the gallery.
This is not a solution to your problem, but some general information that may help. To be clear for others, the facility mentioned in the question is the Gallery (Tools > Gallery) which uses the term “theme” to indicate the creation of a new gallery. These galleries are compound objects stored by default under the user profile in the gallery/ directory i.e., creating a “New theme” (the default name) will appear as a triplet of files:
- new theme.sdg (gallery)
- new theme.sdv (gallery view)
- new theme.thm (theme metadata)
If multiple galleries (themes) have been created then there should be a corresponding number of files as indicated. The size of the gallery file (SDG) should also be indicative of the number of images added to it.
This facility is very old (StarOffice) and now contentious. There have been recent attempts to deprecate it (fdo#30744) but it requires making the old artwork available via some form of online service, or extension, for the sake of compatibility.