Add me to the list… I have the same problem. The only difference is that when I render the video using the Main Concept MPEG-2 using the template DVD NTSC video stream, teh video file created has a .M2V extension. But the same error occurs when trying to import into DVD architect.
I am using a brand new HP dv6-1350US laptop, and have not loaded any other software except for the Sony Vegas and DVD architect. If anyone has any ideas, please let us know.