There are risks involved if you attempt to unlock an HD-A2. If done wrong it could render your unit useless.
Since I had 2 HD-A2 players I decided to take the risk.
I have an australian contact who had a modified 2.501 firmware hack which he gave to me.
Here's how to unlock the player: install rollback 1.6.iso then install modified 2.501 then install firmware 2.8
I was really nervous doing it, because I did not know what to expect.
It worked for some people and it did not work for others.
Fortunately, after a long half hour my HD-A2 is finally Region Free!!!
Caution: Babala: even if I was successful in unlocking my player, I still do not advice doing it because I'm still not confident how it works.
the next day I attempted to try it on my other player(which is brand new and for sale by the way) and it's also region free na rin