Synology DS213+ - Some MPEG-4 videos with missing thumbnails

Hi Guys,

I've been using Serviio on my Windows Vista PC for some month with great results, streaming all my privat media and some recordings via LAN to my LG 42LM640S TV. The recordings are mainly from my Technisat Technistar S1 receiver and from my digicam.
Some days ago I installed Serviio 1.2 on my new Synology DS213+ NAS and all is fine except of one detail. All MPEG-4 videos (720p) recorded with my Technisat receiver do not have thumbnails now. The Serviio server on my Windows Vista PC generates thumbnails for the same files, but not the Serviio version on my Synology (both version 1.2).
Generating thumbnails for the MPEG-2 recordings from my Technisat receiver works fine on the Synology DS213+ Serviio version, too, also generating thumbnails for MP4 videos of my Sony DSC-HX1.

Hope you can help,
Christian

I posted something similar on the 'sony' threads - when I put 1.2 on yesterday, I could no longer see any of my MP4 files (episodes) - I could still see the folder placeholders as if it found the mp4s? - and I had been able to earlier that day on v1.1
so today I uninstalled v1.2, re-installed 1.1 and voila - my MP4 files all play again!

theres def. something wrong with v1.2
(please dont take this as unapreciation!)