Description:
Hi,

I recently moved to Ubuntu and I'm using .pptx files and I realise that each transition has a rapid white flash in between and it's a bit laggy too (the transition feels sluggish), in general,  transition starts then mid way you get a white flash. Please see video below


https://drive.google.com/file/d/0B8_lWwR3sTGoX3VKdC1qeVA3SWc/view

Versions of LO impress that have the issue 5.1.6.2 and I updated to 5.4.2.2 and the issue remains.

Also I'm not using OpenGL and all options in Tools -> View -> Graphic Output I have disabled  ( by default though hardware acceleration and anti-aliasing were checked).

Steps to Reproduce:
1.Open a .pptx file with transitions
2. Start slideshow
3. Click/press a button to induce a slide transition.

Actual Results:  
White flash across screen

Expected Results:
No white flash across screen.


Reproducible: Always


User Profile Reset: No



Additional Info:
Version: 5.3.6.1
Build ID: 686f202eff87ef707079aeb7f485847613344eb7
CPU Threads: 4; OS Version: Linux 4.10; UI Render: default; VCL: gtk2; Layout Engine: new; 
Locale: en-GB (en_GB.UTF-8); Calc: group


User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.75 Safari/537.36