Please, try comparing the video file hashes calculated by Subdownloader and Oscar or at least provide an example filename and filesize so we can analyze this. What release of Oscar are you using? Oscar is "g2v10" This in an example picture of subtitle-search for .mkv -moviefile. In OSCAR ...

Does this OSCAR-program use the same "hash-database" as Subdownloader. (Can OSCAR find those subtitles uploaded in Subdownloader? Because it seems that it can´t) I have lots of .mkv movies and OSCAR can´t find any subtitles for them! Subdownloader finds over 10 subtitles for the same video...