Impress resolution change breaks slide layout

I’ve created a slide series on my laptop using LibreOffice Impress 4.1 under Windows 7. The screen resolution is 1680 x 1050. I set the page layout for the slides to Screen 16:9 and saved in ODP format.

I then placed the ODP file on my Raspberry Pi, which uses LibreOffice Impress 3.6. Sadly - there doesn’t appear to be a port to Arm for 4.1 on their distribution (unless you know of an alternate repository!). The Raspberry Pi is connected to an HD projector, giving it a larger resolution than my laptop 1920 x 1080.

The slides have shrunk when I play the slideshow. Same fonts are on the Pi, but what fits fine on the slides on my laptop is now overlapping on the Pi. They look awful.

This make no sense to me at all. More resolution, but the text no longer fits and everything is jumbled and overlapping. All the images come across fine though… they get scaled and keep their positions. It is just the text that looks awful. Never had this issue with PowerPoint… but obviously I can’t run powerpoint on a Pi!