I'm not sure it is a correct way of solving the problem. Beacuse I won't make visitors of the site to update their players.
SWF and index.php files are absolutely the same on both servers.
You can set your movie to work with a specific Flash player version. Then you can test for that version on your website as the minimum version that will allow your Flash movie to be shown. Otherwise you can show the site visitor a message that they will need to update their Flash player.
This is a very ordinary process.
very strange critical bugs in Internet Explorer and Chrome browsers
Very unlikely that that is the case. Much more likely that it's something else.
as you can see
No I can't see. On my main computer (I don't update to latest version of anything) nothing displays in either FF or IE. As Rob mentioned, you can target versions of the Flash player, but I would NOT advise always choosing the latest version (you have targeted 11.2), instead, for greater viewer access, choose the oldest version that will still work with your .swf... go back to version 10, or less and see what happens.
However, testing on my laptop (with updated Flash version) and IE9, I see no problems, scrolling or otherwise.
Please clarify exactly what the scrolling problem is.... it may be as simple as changing from overflow:hidden to overflow:auto.
These are settings on the HTML settings, not .swf settings.
The problem is solved.
The reason of it was in hosting sutep.
gzip on the hosting was turned on, and that's why flash could get the size the of file being loaded — bytesTotal retured 0 (zero). My preloaders for preview pictures on the page where trying to get size of the loaded files, but unsuccessfully. And bugs appeared — preloaders' height was about millions pixels (infinity). So the scrolling calculation function failed.
Details on the problem and the solution are here: http://patrickmcd.com/2009/04/20/flash-preloading-errors-turn-off-gzip/