I have a Slingbox 350 connected to a Humax HDR-1000S 1TB (Freesat/Freetime) box. It's connected via an HDMI splitter and an HDMI -> component converter.
The Freesat box is giving out 1920x1080p at 50Hz. The component converter is taking that via HDMI and sending out 1920x1080i at 50Hz (the maximum the Slingbox will accept from it, go any higher and you get 'weak or no signal' from the Slingbox, even though it's displaying fine at all resolutions when connected direct to the TV - no big deal though, 1080i is enough for me).
Now here is the weird bit... All is good when the STB is already switched on, the stream is very stable and excellent quaity. But when you switch the STB on from standby to stream - it shows a start-up screen containing the manufacturers logo for a few seconds, at 576i, before flicking over to 1080p for a an animated Freesat logo - then it obviously stays at 1080p when it's booted and showing TV pictures/EPG/etc - this appeared to freak the Slingbox out and causes it to reboot, twice - taking at least a minute or two to recover and be able to stream again, which works OK after this because the box is already on when you reconnect.
Now, I thought this was to do with the intro screens (which cannot be disabled by the way) and the change in resolution - even though the converter should be giving out a constant 1080i50 - I thought the flicking between the different input resolutions on STB boot up was causing some flicker on the output and confusing the Slingbox to freak out - so I thought I'd either have to get a better, more stable converter box, or just put up with waiting a few minutes for the box to recover then reconnecting when ever I wanted to watch something and the STB was in Standby.
Now here is the really weird bit - I noticed today that it doesn't happen when I use the webplayer in a web browser on my computer - this behaviour only occurs when using the android app - which I use to stream to the Chromecast.
When using the webplayer - all works perfectly, you can switch the box on from standby, the intro screen and the animation display (flicking between resolutions), all are streamed, then when the box is booted it continues at 1080i50 - no crashes.
When you try the same via the android app, it crashes the Slingbox.
I find this incredibly weird, as you would think that commands/the stream/whatever are all identical, just sent from a different location?
Any ideas why this happens? It's really annoying, and considering the fact that the Android app cost £10 on top of the cost of the Slingbox - it should be perfect!
Sorry that was a bit convoluted - hope it made sense!