mclean: A couple of things: The profile of the sill is wrong for a door that's exposed to rain - it should have an up-stand at the threshold. Also it's hard to tell from the pictures but the thing you've installed at the bottom looks more like a draught excluder than a weather stop.
Your best bet is probably to fit a proper aluminium threshold plate across the sill, and a mechanical bottom seal on the door that seals against the threshold plate. A mechanical seal is one with a rubber seal that mechanically presses down on the plate when the door closes. You may need to undercut the door to get the threshold plate in - if you do then re-prime and paint the bottom edge before re-hanging it. Also make sure the threshold plate is tight and sealed against the jambs at each end so that any water coming down the door edges drains out rather than in.
Check the Raven website at www.raven.com.au. Mitre-10 has most of the seals, but you may have to order the threshold plate.
There seems to be an Al threashold you descrbe on the sides of the door - but not the bottom - so what you are saying makes sense to me - we may need to find a Hire a Hubby type to do it though



