Just wanted to notify anyone following this thread. New search index folders were added by Subsonic v4.2 and needed to be copied back to non-volatile memory.
I update subsonic_copy_from_memory.sh file in scripts04.zip. (/var/subsonic/data/lucene/ has three sub directories). Bold lines were added...
####################
# Copy data files
####################
DIRFROM="/var/subsonic/data"
DIRTO="/boot/subsonic/data"
if [ -d $DIRFROM ]
then
# If the destination folder doesn't exist, create it
if [ ! -d $DIRTO/db ]
then
logger -s "### $DIRTO/db was not found...creating ###"
mkdir -p $DIRTO/db
fi
# If the destination folder doesn't exist, create it
if [ ! -d $DIRTO/lucene ]
then
logger -s "### $DIRTO/lucene was not found...creating ###"
mkdir -p $DIRTO/lucene
fi
echo "### Copy Subsonic From Memory ###"
cp -Rv $DIRFROM/db/* $DIRTO/db/
cp -Rv $DIRFROM/lucene/* $DIRTO/lucene/
cp -v $DIRFROM/* $DIRTO/
sleep 3
fi