Kwave doesn't import mp3 files

Hi,
I'm running Kubuntu 13.10 beta2 amd64 port Kwave version:

~$ kwave --version

This is kwave v0.8.10 (compiled for KDE 4.10.3)
Qt: 4.8.4
KDE Development Platform: 4.11.1
Kwave: 0.8.10

In order to have Kwave importing mp3 files I had installed:

ii lame 3.99.5+repack1-3 amd64 MP3 encoding library (frontend)
ii libmad0:amd64 0.15.1b-7ubuntu2 amd64 MPEG audio decoder library
ii libid3-3.8.3c2a 3.8.3-15 amd64 library for manipulating ID3v1 and ID3v2 tags
ii libid3-tools 3.8.3-15 amd64 ID3 Tag Library: Utilities
ii libid3tag0 0.15.1b-10build3 amd64 ID3 tag reading library from the MAD project

When I run Kwave from the console I got:

~$ kwave /mnt/pathtomp3/xyz.mp3

This is kwave v0.8.10 (compiled for KDE 4.10.3)
QDBusConnection: session D-Bus connection created before QCoreApplication. Application may misbehave.
QDBusConnection: session D-Bus connection created before QCoreApplication. Application may misbehave.
MenuNode '&Crop': icon 'crop' not found !
      codec_flac 2.3 written by Thomas Eschenbacher
       newsignal 2.3 written by Thomas Eschenbacher
       normalize 2.3 written by Thomas Eschenbacher
        fileinfo 2.3 written by Thomas Eschenbacher
    notch_filter 2.3 written by Dave Flogeras
            zero 2.3 written by Thomas Eschenbacher
        sonagram 2.3 written by Thomas Eschenbacher
            goto 2.3 written by Thomas Eschenbacher
     pitch_shift 2.3 written by Thomas Eschenbacher
           about 2.3 written by Ralf Waspe & Gilles Caulier
          record 2.3 written by Thomas Eschenbacher
          memory 2.3 written by Thomas Eschenbacher
       insert_at 2.3 written by Thomas Eschenbacher
     codec_ascii 2.3 written by Thomas Eschenbacher
 codec_audiofile 2.3 written by Thomas Eschenbacher
          volume 2.3 written by Thomas Eschenbacher
     amplifyfree 2.3 written by Thomas Eschenbacher
     selectrange 2.3 written by Thomas Eschenbacher
         reverse 2.3 written by Thomas Eschenbacher
       band_pass 2.3 written by Dave Flogeras
           noise 2.3 written by Thomas Eschenbacher
      samplerate 2.3 written by Thomas Eschenbacher
error in '/usr/lib/kde4/plugins/kwave/codec_ogg':
         Cannot load library /usr/lib/kde4/plugins/kwave/codec_ogg: (libopus.so.0: cannot open shared object file: No such file or directory)
       codec_wav 2.3 written by Thomas Eschenbacher
        playback 2.3 written by Thomas Eschenbacher
      saveblocks 2.3 written by Thomas Eschenbacher
         lowpass 2.3 written by Thomas Eschenbacher
---
 found 26 plugins

SignalManager::loadFile(file:///mnt/pathtomp3/xyz.mp3) - [audio/mpeg]
unknown file type
--- meta data ---
-----------------
TopWidget::loadFile() failed: result=-22

Could anybody tell me how do I get Kwave working with mp3 files?
TIA
Franco