They seem to reencode quite frequently, so simply remove the md5 sum.
@ -16,7 +16,6 @@ class ImdbIE(InfoExtractor):
_TEST = {
'url': 'http://www.imdb.com/video/imdb/vi2524815897',
'md5': '9f34fa777ade3a6e57a054fdbcb3a068',
'info_dict': {
'id': '2524815897',
'ext': 'mp4',