Problem with OSMC and Kodi . Movies and voice have time shift

hello to all,

hope my english is good enough to describe my problem.

First - I have:
1 NAS
2 Raspberry Pi Model 1 B
1 Raspberry Pi Model 2
all connected by LAN

Now this year, when I got the new Raspberry Pi 2, I used to listen to the suggestion of people to use the new OSMC with Kodi to stream my movies (*.ISO, *.IMG (DVD5 & DVD9) as well as *.MKV) from NAS.
Before, I was using RASPBMC and Kodi and I seldom got problems.

Because of the Model 2 I wanted to try OSMC and it worked - for first.
Playing Movie from regular hard disk drive does not make any problem, even I use BluRay.quality movies.

Now when I try any kind of Movie from the NAS, it takes several minutes, then there is a time shift between the picture and the voice.

on my old Raspberry I went back to the RASPBMC with XBMC. And there is no problem. If I use OSMC + Kodi, I have the same negative effect on my older Raspberry.

So my Question is - if there is any kind of setting I should use or maybe any special version I can use for not to see this problem.

im reading this right? you want play image files (*.img, *.iso) as movie? is this even possible? … try copy some movie from the mentioned harddrive to your NAS and you will see…

video formats are *.avi, *.mkv, *.mp4 and so… as i know files like *.img, *.iso are used for software/os images, not movie images…

Yes, Kodi can play .iso files: http://kodi.wiki/view/Features_and_supported_formats#Video_player

ok then, sorry for my mistake…

@Wolf_359 - all your mentioned devices are connected to your LAN with ethernet cable?

Yes Mio,

all devices are connected to the router via ethernet cable

and thanks for answering

np, what kind of hardware is on your NAS?

My NAS is a QNAP TS412 including 4x4TB HDD
OS is newest Version

but meanwhile it seems I found something by myself. Must be one of the settings I used.
Just at the moment I am not really sure about it.

So, after long time searching, do the trial and error through all the settings I definetly found the mistake with one or more wrong settings.
Still I am not sure, which setting was wrong, because I’ve changed several at one time.
Not very scientific, but it worked.

Anyway thanks to all