Did Transphasics get a recent buff? I haven't seen anything on it, but my Transphasic Cluster Torpedo has been doing some ridiculous damage, even through shields, of late. Unshielded hits are yeilding 4000+ dps per mine while even through shields each mine is scoring over 1000. This weapon used to be completely useless but now suddenly seems to be awesome in terms of burst damage.
I'm not sure, but I have noticed that it is more useful. I am using it until I get the romulan reputation torpedo, and I've actually found it to be rather useful. It actually helps. Not sure if it's just more passive torpedo buffs, but I'm liking it.
I don't know how far back you are talking, but there have been a couple.
When they buffed mines they made some changes to the cluster torp as well, and then in a later patch they helped its AI a bit. It fires more consistantly and actually spreads instead of vanishing half the time. Part of me wants to say they increased its flight speed and lowered the amount of time it takes for the mines to activate after deployed as well, but I can't memorize every patch note ever...