Bitmap scale issues

I couldn’t find any specifics to this problem online after some looking so i figure I would ask you guys if you have run into this before and maybe get an explanation.

When i created a Bitmap object from drawling the pixels of an image and then scale that Bitmap too large (or even too small) the image disappears or in some cases distorts in what appears to be random pixels barfed all over my screen.

in order to show you this I have made an example:

http://troyblank.com/temp/kirupa/bitmapScaleIssue/
(click the plus button any more than 8 times and poof! the bitmap disappears)

and source:
http://troyblank.com/temp/kirupa/bitmapScaleIssue/source.zip
(flash cs4)

any insight into this issue or bug would be greatly appreciated.