Yesterday I got the same error message. The message was not only for the video (MPEG2) but also for the menu background (a still that I created in photoshop and imported into DVDA as either .jpg, .tiff, ,png or .psd).
More funny, I got the same error messages when I tried to burn with DVDA Studio.
The DVDA used was the latest version, installed on a new Windows 7 64bits PC.
Since nothing helped, I just uninstalled and re-installed DVDA and then the problem was gone.
Probably this will help for you too
Theo