image loaded successfully, but fail to draw bitmap of it

I  have a image loaded from  different domain. The checkpolicy is set to  true and crossdomain file  has no problem.  The image isn't that large,  2,304px × 1,260px

In the application, I will draw the bitmap image with this call

new Bitmap(Bitmap(imgLoader.content).bitmapData, "auto", true);

The   weird part is, there is 1% chance... the application can't draw the   bitmap... it will just be empty. It never happens to me, but some of my   users are complaining they can't see any image. I think they have  pretty  decent computer, and see the application on ie8 or ff4

Not   sure is there anything I am doing wrong... I am sure the image is   loaded to user's browser, but the application just can't draw it....

Can anyone help?

Thanks a lot