Flash player 10 debugger/browser problems... need some insights

hi
I have been working with flash for quite sometime. I have been having issues with the debugger a lot lately.
The debugger throws a popup with the error content on firefox which hangs up the browser causing the flash plugin to crash.
This happens mostly in the following cases.

There is a load on the server and then the server turns 500 or something like that then my flash trying to fetch an xml through db query doesnt get it.

My flash is loading and in between the page is refreshed.
(In this case i get “Load never completed” error)

Also gets xml markup language error sometimes.

And I do not know WHY this ONE COMES “#2000:No active security content”, or How to fix this

I use as3 to code.

At first i thought disabling firebug and flash console might help but didnt

I keep thinking maybe IOError handler should fix this but it still throws me the dialogue box on firefox

Or does the “try catch error” should be used.

How do i stop that popup from coming up and hanging firefox.

Please provide some insights…
Thank you in advance