Can't Trace

It was still working some hours ago but now, it is not. Before that, I could still trace message and the output window will just pop up and show the message. But now, no matter how I trace, it don’t show up in the output window anymore! I dont think my syntax has any problem. This is what i typed:
trace(“test”);
I put this code at the first frame of the stage’s timeline and ran it.
I tested this on both Flash MX and 2004 and they both don’t show the output window with the message at all. I tried opening the output window and then run but the output window shows blank!

After this, I tried it in Flash 5 and it worked well. The output window showed the word “test”. Kinda weird? Did I accidentally set anything I didn’t notice that caused this?
I am a little new to actionscripts as I am always into tweening until recently. Hope somebody can help me…thanks…