Guys, I switched sampling rate to 16 kHz and recorded an incoming call 1 min 30 sec length. It really does play back with glitches on the device and the progress bar is faulty but I could play it back normally on my desktop Fedora with VLC, Rhythmbox and Audacity.

Actually this is exactly what was written in the top post and the README file upon release of the Call Recorder 0.4. There was a paragraph regarding sampling rates other than 44.1 and 32 kHz which may cause this type of problems. I don't really know how to address it now, guess we should just try and wait until Jolla upgrades to gstreamer-1.0. If it's not happening any time soon or won't help, I'll try and work this around with direct decoding using libFLAC.

What is really interesting is that VLC crashes when HtheB tries to play back his file. Can you please check if this file can be imported to Audacity?