mp3gain vs madplay

Peoples,

I'm about to launch into a debugging session to see why mp3gain 
(http://mp3gain.sourceforge.net/ ) and madplay 0.15.1b don't seem to be 
playing together (no pun intended). I thought I'd ask if anyone has used 
the two together yet, or if there is another linux-based replaygain 
processor (for adding replaygain to existing mp3s) that is more reliable.

map3gain does appear to be adding a tag, as it finds it again if rerun 
over the same file.

"# mp3gain /tmp/Abracadabra.mp3
/tmp/Abracadabra.mp3
Recommended "Track" dB change: -1.690000
Recommended "Track" mp3 gain change: -1
Max PCM sample at current gain: 28533.063680
Max mp3 global gain field: 180
Min mp3 global gain field: 116


Recommended "Album" dB change for all files: -7.490000
Recommended "Album" mp3 gain change for all files: -5"

madplay doesn't appear to find it:

"# madplay -G -Tv /tmp/Abracadabra.mp3
MPEG Audio Decoder 0.15.1 (beta) - Copyright (C) 2000-2004 Robert Leslie 
et al.
          Title: Abracadabra
         Artist: The Steve Miller Band
          Album: Golds Greatest Hits
          Track: 11
           Year: 1982
          Genre: Vocal
Encoder Version: LAME 3.92
     VBR Method: constant
        Bitrate: 255+ kbps
    Stereo Mode: normal
         Preset: none
Unwise Settings: no
 Encoding Flags:
 Lowpass Filter: 19500 Hz
       ATH Type: 2
  Noise Shaping: 1
       Surround: none
    Start Delay: 576 samples
    End Padding: 1503 samples
    Source Rate: 44.1 kHz
   Music Length: 9948263 bytes
   Audio Frames: 11900"
(note the missing "Replay Gain" printout I expect after reading the source)

I'd hasten to add that I suspect mp3gain of doing something wrong, not 
madplay. I'm guessing the tag is wrong or in the wrong place.

Any info would be appreciated, otherwise I'll report my findings to the 
list when I discover the root cause.

/Bruce