Hi,
I dont know if this helps, but Im getting the same errors as you do when I decode small mp3 files who is just a part of a song. My experience is that these errors does not effect the decoded file. Have you tried to play the decoded .pcm file? I do so with Audacity (http://audacity.sourceforge.net/, I import .pcm file as raw audio data in the project menu) and I cant say there is anything wrong with the decoded file, at least from just listening to it.
Regards,
H.