Question about upgrading my version of flash

1

If I upgrade my dreamweaver version from the FlashMX version 6 to the Flash8 dreamweaver suite will I still be able to edit my website that I have created and edited with FlashMX version6? This may be a really stupid question, but I seem to get “Unexpected file format” on almost all of the source .fla files that people put up for others to download and learn from, and I am worried that the same thing will happen if I upgrade my software in the middle of my site development. My hope is that any upgrade to my current flash version will just be backward compatible? Thanks.