Default program to run at specific file extension

I have a problem. I've been using linux for my nas, but in the last decided to give up using windows, so i started to use mate ask desktop as well.

I wanted to select movied which have been recorded my tvheadend, the files have .ts extension.
If i click in the caja on it, caja wants to be added to skype.
So i selected right click, properties , open with - Add
i choose vlc as player, and add, happens nothing.
ok, i found, if i add adobe reader, then i can add vlc as well. so i added adobe reader, and vlc, then deleted adobe.. the vlc kept added..
and close the windows, and happens nothing, all settings are lost.

the easier way, right click , open with another app, choose vlc, works, but only once, the "remember this application for ts documents" function doesnt work.

Is it normal behaviuor ? I dont want to be forced to use skype as media player because it is not a media player.. Is there any trick to set the vlc as default program for .ts documents ?

I assume that simply opening one of your .ts files causes it to play correctly?
Could it then have anything to do with the fact that .ts is a wrapper type rather than a file type - a .ts file can contain several file types, unlike a .txt file...
Derek

Finally i found a workaround..
It only happens if its on a network drive. If i mount the samba network drive it works correctly.. It seems to be a bug.