Hi Sam,
I might be abit late looking at the dates. I had alot of problems installing 10.4.4 which I won't go into.
In my opinion, and what worked without fail for me, was to just simply do a reinstall of your system (Install and Archive NOT clean install, unless you want to lose everything on your system)
Just for the sake of it, simply place your Install Disc in computer and startup holding down the 'C' key (it may take a while), and when screen appears click through following prompts to you reach install options. Again make sure you select the Install and Archive option (cant remember exactly what it says, should come up already ticked as first option anyway) and proceed from there. Will take anything from 45 to 90min. You will need to have the second disc handy for when prompted. The only thing I would say about the second disc is that when you are asked to insert it, in my case it did not automatically eject the first one, so press the key on your keyboard that is the furthest most right at the top above the numbers part of the keyboard (next to the volume keys).
The install and Archive (from my experience) is fantastic, as it leave all your programs, settings etc (including internet access) exactly as they were. You should notice little or no difference except you will have a nice new pristine operating system.
Once you have done this, don't worry about manual downloads etc, just go straight to software update (click apple button, top left of screen, and select software update) and go for it. I doubt you will too many problems after updating to 10.4.4 once you have done this (again from my experience of it),
but if you don't want to install 10.4.4, then simply untick it from selection.
If you choose not to install 10.4.4, then once all other updates are done, you may want to do a manual search and download of 10.4.3 combo, as this has some updates that your original discs won't have.
Again, don't know if you have already solved this, but may be of some assiatance.
Timberman 🙂 🙂