Some functions not working in DFRobotDFPlayerMini.h

I have a lot of the functions working, play/next/loop etc. but I can't get the functions that return information to work.

maxSongs = myDFPlayer.readFileCounts(DFPLAYER_DEVICE_SD);
Serial.println(myDFPlayer.readFileCountsInFolder(1));
Serial.println(myDFPlayer.readVolume());
Serial.println(myDFPlayer.readVolume());

are some that don't work.

Any Ideas?

Start here

I must assume that the library is faulty. I used the example that came with it but got no returned values from the DFPlayer mini. I thought it could be my player faulty but I found another library ( DFMiniMp3 ) and that returns volume, eaqualizer settings etc.