FreshView is a freeware program for image browsing/cataloging that does much more, including converting a folder (or folders) full of images.
RE: V/Dub... Had some jpegs not work, but not the error posted -- Generally open the sequentially named images using the file open dialog, then select things like the codec. Is it possible you already had codec selected, & that problem was with the codec not accepting anything not YUV?