Swf behavior change

anybody ever seen an swf behave differently after it’s been embedded in html and put on the web?
i’ve got a file that’s perfect (to me anyway) on the desktop as an swf, but it does bad things after it’s out on the net.
things i can’t duplicate on the desktop…

it’s too complicated to do in detail, but i’m loading external pix and they’re centered as a local file, but come up waaay off center after it gets uploaded.

that’s the only change. could it be a delay due to the loading of the file or something? never heard of this…