something looks strange...

i have a .swf file. when i try he "test movie" function, the window tells me my file is 231ko total.
i test the bandwidth (i included a loading), and...
the movie loads, loads, and go to 100%. but what is happening, the loading bar continues to grow, and the ko loaded too!

results:

total size: 231ko
ko loaded: 316ko

what is that?