How and when does [SWF] - xxx bytes after decompression occurs

I have a program that load a lot of images, but when there too much loading going on, it freezes and jerks the hell out of my program. I have tried a lot of tracing from beginning to the end of the loading process, which things looks fine and behaves as I expected. However, every time the program jerks it outputs couple hundreds of these "[SWF] - xxx bytes after decompression" message in my console (almost all at once), and it came out of nowhere, when I tried to bracket my image loading progress with trace statem开发者_开发知识库ents like putting a starting trace and a ending trace, these messages does not appear inside, its just appears randomly.

So, my question is : does anybody know how and when does this messages occurs exactly?

Thanks in advance for answering the question.