The .swf files were created with XX. I have checked the security settings and can not find any that would appear to block the files. I do not get any type of error messages, warnings, and any mention of needing to go to Adobe or anything of that nature.

I just get an empty block where the .swf file should be playing. I have discussed this with several people who are also familiar with both Flash and IIS (which BTW is version 5.1 becuase I am running Windows XP) and no one seems to have a clue of why this is happening. There has to be a reason

When I put the exact same code and files on a production or test system the pages display fine and the .swf files play. It is just from my localhost that I am having problems. I have been "living" with it by loading the files on my local machine via the development server (which is a pain when I am trying to get feedback from users). At this point I am trying to understand why this happens.

I do appreciate all of the feedback I have gotten and I am willing to explore all suggestions - I want to understand why it happens so I can eliminate the problem on future projects.