Blendop is set to 1 by default.. usually if this problem is happening it's becuase of some Z-buffer error. Transparent polygons cant write to the zbuffer.. if they do nothing behind them will be visible. So, make sure your entity in A6 has the my.transparent flag on, and in your shader set renderstates:

zenable=true;
zwriteenable=false;
alphablendenable=true;

You shouldnt need to set any blend ops or blend modes..if you just want a plain alpha transparency