"pretty sure they are not broken" is no substitute for actually checking them.
From your video, it's clear that a wallpaper is loaded - it then fades out which indicates that it is simply changing to a different picture rather than being unable to load and display on boot-up. Put together, that suggests that your desktop is loading correctly and the problem comes from displaying the second image - which appears to be changing very quickly after you log-in.
If you google for "blank wallpaper" or similar, you'll find that this is a problem going back years - to at least XP. One suggested "cure" (and there are lot sof possible cures) is to disable "shuffle" but that's most like simply down to preventing a problem image from being loaded immediately after boot-up (if it's the tenth image and there's a 30 minute delay, you'd have to use the pc continuously for 5 hours before you'd see the problem).
Basically though, no-one else is reporting the same problem as you and I've tried to recreate it and can't - which means it's pretty-much impossible for Tihiy to try to find a possible cause in his program until you have at least tried to eliminate likely causes specific to your pc.
Please check the pictures as I suggested - maybe try to create a different slideshow using images from a different folder or download a new theme from Microsoft's site - most importantly, check if this problem occurs with the built-in themes and pictures and any that you have created or downloaded. If the problem is happening with every slide show regardless of what theme, storage location and image format you are using, we can try to work out if there's any way that running SiB could possibly be involved. Also. can you tell us some useful information - such as the delay you have between slides, whether or not you are running any tweaks or hacks (such as gui themes, transparency apps etc) and any other start-up programs and apps you have running - just in case there's something hogging your cpu/gpu at start-up - if that's the case, it could be that stopping any one start-up item would release a few clock cycles rather than it specifically being down to SiB.
If you can definitely eliminate every BUT SiB, then we'll need to know details such as the version and your specific settings to be able to start to work out where the problem could be.
This post has been edited by pengipete: 22 March 2013 - 07:33 AM