When I loosen the cable, it doesn't allow the derailleur to move out enough to use the highest gears without the chain rubbing.

Basically, my procedure was as follows (ion case I'm doing something wrong):-
1. Set chain to largest rear cog and smallest front cog
2. slacken cable from FD
3. Screw 'low' screw all the way in, and then unscrew until chain just clears inside of FD
4. Pull cable hand tight and secure
5. Set chain to smallest rear cog and largest front cog
6. Screw 'high' screw all the way in, and then unscrew until chain just clears outside of FD

Basically, I have now raise the FD so the inside clears the middle ring, but in step 6 I can unscrew the high screw all the way and the chain still rubs the outside of the FD. If I tighten cable slightly to push FD out so it clears, the chain then rubs the inside of the FR when using the lowest gears (smallest front cog and largest rear).