I know next to nothing about how Linux works but, when I updated from mt-daapd-0.2.4 to mt-daapd_svn-1372-1_armeb.ipk I dropped mt-daapd_svn-1372-1_armeb.ipk & libao_0.8.6-1_armeb.ipk into the public folder on my slug from windows and then via telnet:
cd /tmp
cp /share/hdd/data/public/mt-daapd_svn-1372-1_armeb.ipk /tmp
ipkg update
ipkg install gdbm
ipkg install libid3tag
ipkg install -force-overwrite mt-daapd_svn-1372-1_armeb.ipk
cp /share/hdd/data/public/
ipkg install libao_0.8.6-1_armeb.ipk
After re-booting the slug, everything just worked.