Well everything is in and up and working and life is good with 38Megs up and 8.9Megs down!!
Perhaps you really mean 38 Mbps DS and 8.9 Mbps US ?
That minor typo aside, it's excellent news.
So you have obtained an
HG612 modem, uploaded the unlocked SP10 firmware to it and configured it appropriately for PPPoE. When using an old router to provide just DNS/NAT/routing/WAP for you LAN, all was well.
Now you wish to revert to using the
HG612 in its original configuration, as a pure bridging modem. After performing the "long reset", I would advise re-entering the modem's GUI and deleting the
BT firewall. That will ensure it is not inadvertently re-applied. As far as I can tell, nothing else should need to be changed.
It does seem as if your problem is with the
HH3A . . . I am surprised to read that they are "locked-down" devices. The
HH3B most definitely is
not locked and the
BT documentation even has a section about their use on a non-BT Broadband Service.
Perhaps the best person to comment will be
Asbokid . . .
Edited to add: Please post a link to the explicit instructions that you have followed when hacking the
HH3A.