I have still the problem, by some random movies i got the error
"Playback was not possible: not enough bandwidth for any playback of this item.
Cannot convert to below minimum bandwidth of 311kbps."
I didn't set a bandwidth limit and have a fiber connection with 500mbit upload speed.
Andriod is the last version and also the server version (1.2.4).
If i replace the file for a other one then the problem disappears ;/