Ed
I used a now unavailable online guide to install to hard disk. I'm glad I printed it off! Anyways, this guide says you should ensure Aros goes on a partition smaller than 4GB.
He recommends downloading Ultimate Boot CD and using Ranish Partition Manager to partition your drive rather than HD Toolbox.
You can use HD Toolbox to do everything else, just not the partitioning.
I also couldn't get the installer to work so just manually copied everything over. It took a while but worked fine.
Dunno if this'll help, but worth a try?