A similar problem has just occurred for me. I have had no difficulty creating wmv straight from avid sequences until last night. Now the wmvs render as two halves of the vertical height transposed over one another and stretched to fill the height parameters. All other file types (AVI, quicktime etc) continue to render appropriately. No changes have been made to any settings from the last time I created wmvs a couple of days ago when everything was working fine.