Trying to burn a project made up of MP4 video files (about 2 1/2 hrs in length) and when it reaches about 97%, I receive this message "Device Error - Sense Code (6 28 00) - Not ready to ready change, Medium" and then Premiere elements 9 procedes to burn a perfect DVD with menus and all. Any ideas?
You're likely to run into a lot of problems trying to edit MP4s in version 9. That file format isn't fully supported until version 11.
And that's compounded by the fact that it's a Spielberg-length project. Far too long for a standard DVD (which holds only about 70 minutes of full quality video).
But if it's still working for you at a quality that satisfies you, I guess you can ignore it for now.
SenseCode errors are most often caused by hardware issues with a multi-drive (burner), and can be from perhaps old firmware in the multi-drive, or connection issues on the system, between the multi-drive and the OS. I would first check for firmware updates from the multi-drive's mfgr's. Web site. Be sure to read the instructions for "flashing" the ROM with firmware updates - VERY IMPORTANT - follow those instructions to the letter!
They can also be caused by blank media issues, such as bad blank media, non-RW media, that has been used already, or RW media, that was not erased.
What brand, and type of blank media are you using?