Subtitles priority in mkv container

I want to mux several streams - 1 video, 1 audio and many subtitle with MKVMerge and I want to players by default show Serbian subtitle. There is my problem: if is English subtitle present in mkv, than players always set English subtitle, even if I set Default track flag: yes for Serbian subtitle. Is there a way to force this subtitle to show as default? Thanks in advance!

Thank you for your answer. I always put Serbian subtitle first, but that doesn't help. Here is another strange behavior: when I put Serbian, Croatian and Slovenian subtitles, KMPlayer as default display Slovenian subtitle, but when I put Serbian and Croatian subtitle then KMPlayer display Serbian subtitle. I don't understand what is going on. In Haali's folder I can only open gdsmux, but this is for muxing streams. :confused:

There should be a start menu entry called "Media Splitter Settings" that will bring up the configuration panel for Haali. You might want to test with mplayer as well.

During the installation of Haali splitter I didn't choose that option. I tried with MPlayer and problem is the same as with KMPlayer. Even when I set for default subtitle Serbian, then MPlayer doesn't show any subtitle. Thanks anyway.