If two slides have the same name (in this case, slides were imported from a pptx document and saved as .odp before editing; names were carried over from powerpoint) and I try to move the second one, it gets replaced by a copy of the first. Renaming the slide fixes the problem.
Steps to Reproduce:
1.create two slides with the same name and different content in a multislide presentation
2.move first slide: the content should stay the same
3.move second slide: gets replaced by a copy of the first slide
content of second slide gets replaced by a copy of the first slide
content of second slide should be unchanged
User Profile Reset: No
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:57.0) Gecko/20100101 Firefox/57.0
Thank you for the report. Fixing bug 103347 will also solve this, so I will close as duplicate.
*** This bug has been marked as a duplicate of bug 103347 ***