Please help!

I am trying to use Dreamweaver to publish my website I created in Flash to the web. I was successful in getting it published about two weeks ago then updated something and tried to republish it. Now when I preview in IE from Dreamweaver, the embedded .swf just flashes quickly then goes away. Also when I try to actually access the website online most of the time it does the same thing - just flashes quickly. Other times all that shows up is the black background, but the actually .swf won’t open. I cannot figure out what might have changed from the first time and desperately need some help please!! Thank you!