serviio does not recognize avi/mkv files

I'm running serviio 0.6.2 in linux ubuntu 12.04.
Serviio sees and scans all multimedia files (audio, e.g. mp3, pictures, e.g. jpeg, and video, e.g. mpeg/mpg, avi and mkv) but on the TV I can only see jpeg, mp3 and mpeg/mpg in the related folders, no avi/mkv at all, the folders containing avi/mkv are displayed as void (there are no element to be visualized).
Any suggestion?
Thanks!

[jabrown0604]

Make sure your device has the correct profile, and Second check the logs to see if it is having problems with specific files.

the first one, thank you, don't know why but the profile was not the usual one, but the generic.