I have found that when compression is needed on say a 2 & a half hour film onto a 25gb blank, you must be sure to update video card fimware, & also remove all the extras on the film, & most important remove the HD audio as this takes up a lot of room.I have found contrary to opinion, that it seems more successful compressing straight from the disc to the hdd.This I must add should only be done if you have a fast pc, otherwise copy to hdd first.I have found from experience that a compressed copy could skip without doing as suggested above.I know in some cases it depends upon your pc as whether this is the rule of thumb--but it is worth a try.