Macromedia Flash supporters are going to have to rework their code as IE has now been fully patched to essentially disable interaction with Flash elements until the user clicks on the element to enable it.
Some may think of this as a godsend, but for developers who use flash in navigation elements of their site (a bad practice) or who use Flash for key interactivity features of their site (a questionable practice) this comes as a great blow to their productivity.
The workaround is simple, use FlashObject – a DHTML loader for Flash elements. It supposedly fools IE into allowing Flash element interaction without clicking beforehand.
The reason why Microsoft decided to do this is in response to a long-running lawsuit between themselves and a company started out of the university of California called Eolas.