Really dumb question probably, but....I just tried to burn a DVD-R with a slideshow I produced. I've burned CDs before, but this is a first for DVDs. I have an iMac 24", purchased in early 2009. Anyway, it burned fine, but when I tried to open it I received a message, "An error occurred while loading the project. This project seems to be write-protected and can't be opened." Could it be that my iMac can't burn DVDs. Or, did I do something wrong? Any help would be appreciated.