to remove black edges you need to do:
open the _ori tga in photshop, select the area where the black edges appear in game, activate alpha channel, go to Edit->Fill and choose black and ok. save it
in UnrealED: right click on the _ori file, properties->texture->alpha (something like this) True
i don't know how to explain better
if you don have the Channels window in photoshop go to Window menu and select Channels
hope i helped you
P.S. maybe in photoshop it is already black, it doesn't matter, you still need to fill it with black