Help Cant see subtitle on mvplayer when connecting zt-180 on plasma

[jordan23air]

Hi!Can anyone help me pls? I have a zt-180 4gbram,1 gb ,512 and i have a litle problem.I am running a mkv video from an usb stick with mvideoplayer 2.9.1 and the subtitle work fine ,but when i switch to my tv plasma with hdmi,i cant see the subtitle on tv,it is very strange.
Any ideeas pls.thx