Dear Borislov,

Thank you for your reply,
The solution was as following:

We should change .fullscreen property to .T. or "true" when media player is playing! and by checking .playstate() method and after finding that it is playing by returning 3 (3 will show that it's playing) we should change .fullscreen to .T.

I found it after two hours of challanging.
Farhad