Not playing 22050Hz MP3 files

Hi,

I'm completely puzzled. I'm trying to get the AMP+ to work with Volumio for 2 days now. Turns out I'm using wrong test files.

I followed your Linux 3.18.x guide using mplayer to test the AMP+ (just: mplayer {file})

OK test file:
Playing Josephine.mp3.
Detected file format: Audio only
Clip info:
Title: Josephine
Artist: Chris Rea
Album: Heartbeats (Greatest Hits)
Year: 2001
Comment:
Track: 8
Genre: Rock
Load subtitles in .
Selected audio codec: MPEG 1.0/2.0/2.5 layers I, II, III [mpg123]
AUDIO: 44100 Hz, 2 ch, s16le, 320.0 kbit/22.68% (ratio: 40000->176400)
AO: [pulse] Init failed: Connection refused
AO: [alsa] 44100Hz 2ch s16le (2 bytes per sample)
Video: no video
Starting playback...
A: 16.9 (16.9) of 274.0 (04:34.0) 2.9%


Not OK test file:
Playing 01-Daydreamer.mp3.
Detected file format: MP2/3 (MPEG audio layer 2/3) (libavformat)
[mp3 @ 0x75beef30]max_analyze_duration 5000000 reached
[lavf] stream 0: audio (mp3), -aid 0
Clip info:
artist: Adele
album: 19
title: Daydreamer
TLEN: 220506
track: 1
genre: Soul
date: 2007
Load subtitles in .
Selected audio codec: MPEG 1.0/2.0/2.5 layers I, II, III [mpg123]
AUDIO: 22050 Hz, 2 ch, s16le, 160.0 kbit/22.68% (ratio: 20000->88200)
AO: [pulse] Init failed: Connection refused
AO: [alsa] 22050Hz 2ch s16le (2 bytes per sample)
Video: no video
Starting playback...
A: 2.0 (02.0) of 220.6 (03:40.6) 1.1%

I tested a bunch of other mp3's and it seems that only 22050Hz MP# files are not playing.

Help is appreciated.

regards, Tim