If MAFW reports an error, OMP often spits it out on the console. Run it from the terminal and watch the output when you try to play an .ogg, maybe that will give some clue.
18 - 35 0x0 0 - 17 0x41c0f0 NowPlayingWindow::updatePlaylist | 0 0 0 QNetworkReplyImpl::_q_startOperation was called more than once query 0x41c0f0 complete 0 - 17 0x48a5e8 query 0x48a5e8 complete 18 - 35 0x0
X Error: BadWindow (invalid Window parameter) 3 Major opcode: 31 (X_GrabKeyboard) Resource id: 0x0 NowPlayingIndicator::autoSetVisibility NowPlayingIndicator::autoSetVisibility NowPlayingIndicator::autoSetVisibility NowPlayingIndicator::autoSetVisibility NowPlayingIndicator::autoSetVisibility NowPlayingWindow::updatePlaylist | 0 0 0 playlist type rejected, update aborted NowPlayingIndicator::autoSetVisibility NowPlayingIndicator::autoSetVisibility NowPlayingIndicator::autoSetVisibility NowPlayingWindow::updatePlaylist | 0 0 15 playlist type rejected, update aborted NowPlayingIndicator::autoSetVisibility paused position: 10 Metadata changed: "duration" = QVariant(qlonglong, 2626) Metadata changed: "audio-codec" = QVariant(QString, "MPEG 1 Audio, Layer 2") Metadata changed: "bitrate" = QVariant(int, 160000) Metadata changed: "res-x" = QVariant(int, 640) Metadata changed: "res-y" = QVariant(int, 480) Video codec info unavailable, switching to radio mode NowPlayingIndicator::autoSetVisibility