Soundbridge M1001/Firefly 0.2.4.2
I am not sure a version this old supports Flac…
I’d go to a nightly like 1586 which can be found here
http://nightlies.fireflymediaserver.org/version.php?version=svn-1586
download it to your admin part of the slug, telnet in, cd to the dir you downloaded it to and then type
ipkg install mt-daapd_svn-1586-1_armeb.ipk.
Craig