Flickering transition

Hi,
When I use a slow dissolve transition from black (40 seconds) the image and background slowly flicker.
The image is around 500 KB, jpeg and I have plenty of RAM.
Does anyone have similar experiences?
Thanks,
/Ivar

can you please provide a small sample slideshow and a system profile of your system (https://support.steampowered.com/kb_article.php?ref=4840-QWJX-0408)