synchronization trouble

[ValValVal]

Please help me!
I have two JFrames: ChessBoard and PawnPromotion. PawnPromotion is launched from ChessBoard, and when it is operating I call wait() on ChessPromotion. After user selects piece in PawnPromotion it calls notify() in ChessBoard and exits.

this is the code in ChessBoard

PawnPromotedSelection pps=new PawnPromotedSelection(this,father_board,from);
 
        synchronized(this)
        {
       try{  this.wait();}catch (Exception e){}
         }

This is the code in PawnPromotion when selection done.
mc is the ChessBoard from which it was launched

  synchronized(mc){mc.notify();}
       this.dispose();

Unfortunately it doesn't work well.Strangely enough it works sometimes, I can't understand what conditions cause it to work,but usually it doesn't work.
Additional information: this is part of larger program,it is not possible for me to post all the code.

I would be very thankful for suggestions here.
Val

[cordeo]

try{ this.wait();}catch (Exception e){}

First off all: NEVER ignore exceptions, try writing
try{ this.wait();}catch (Exception e){ e.printStackTrace(); }

and look what is happening.