The description of CloneBD reads "CloneBD makes perfect 1:1 clones, but also compresses BD-50 to a single BD-25" When I place a BD-50 in my "read drive" and attempt to do a full copy to my "write drive" on a BD-25 blank I get the message that there is not enough room on the write drive's disc. I thought compression would take place. Is there a button for that I am missing? Since there is no manual... Later.... ...solved it for myself. As many of you have observed, CloneBD will adjust the compression (slider) so that the recording will fit a BD-25 SOMETIMES. As others note, it works and then on another disc it doesn't work. On one occasion where it still said not enough room on disc I manually moved the slider to the left then reset the media selection from Custom to BD-25 again and the not enough room error did not return. It went through the entire copy and burn but the resultant disc was unplayable past chapter 3; I had sound all the way buy frozen video.