BD-F5100 blu ray, no avi external subtitles

Latest firmware for 5100

Serviio on Windows 7,
MKV & mp4 with external subtitles works very fine, but dont work external subtitles for avi!!!
After profile and transcoding setts... no changes.
And no thumbnails for video files.
FF/RW works.

No problem for Samsung TV, LG TV and ServiiGo.

Any suggestion?

Dito here. Same Blu ray F5100. Everything works perfect but NO video thumbnails. They do show with photo and MP3 covers. But none whatsover with any kind of video files. Tried wmv, mp4, avi, mpg, mkv... All file types work great playing. (surething with baked in subs!) But no artwork. Did all the things needed in settings. Tried everything.. no luck. Besides that, the BD-F5100 isn't recognized as a device either. Further more "the dot" stays orange. (btw . working with Windows 7). Tried every profile settings there is. Any help please? Or can it be the fact that the BD-F5100 can not handle thumbs for video? Bit strange, since MP3 tagging and Photo is just working fine and are showing perfectly.

SRT not working with AVI for me either.
I've tried every Samsung profile, but no difference. I've also tried recoding the srt files from UTF8 w/o BOM to ANSI and UFT8.
Only way it works is if I check "enable burned-in subtitles", but then I can no longer fast forward or rewind (and in some cases even pause).

Samsung BD-F5100 with Panasonic Viera TX-P42X20E (if it matters) and Serviio 1.4.1.2.