Replay Gain information embedded in MP3 files using Foobar's Replay Gain 
Scanner (v0.8.3) is not picked up by SlimServer. Using the web interface, the 
song info displays:

Volume Adjustment:  0.00 dB
Album Volume Adjustment:  0.00 dB

In Foobar's properties window, the same track displays:

REPLAYGAIN_TRACK_GAIN = -4.51 dB
REPLAYGAIN_TRACK_PEAK = 1.024200
REPLAYGAIN_ALBUM_GAIN = -4.30 dB
REPLAYGAIN_ALBUM_PEAK = 1.024200

MP3Tag (V.2.33a) has also been used to tag the files. Note that MP3Tag can 
change the case of ID3 field names (in this example they are all upper case, 
while foo actually writes lower case). I do not believe this (case sensitivity 
on the field name) is the issue though, as I have tried both upper and lower 
case on the same file.

FLAC and M4A files tagged and scanned with the same tools report and appear to 
use Replay Gain correctly.

I Can provide a sample file if required.

Thx.

H.