That's what I thought too regarding 0 Mhz, however the 500 Mhz setting shown for me was completely different to any in FREQS which is rather perplexing (almost as if it isn't overwriting the previous setting)? As you say, I do hope titan can shed some light and/or fix the bug..
for f in $allfreq; do
for f in 0 $allfreq; do