what aros kickstart (image) are you using? hopefully an up to date one, one from nightly?
as for soft kicking aros from amiga kickstart, heres a short introduction, hopefully up to date:
you need to remember than when booting strightly from hard drive you need to edit first line of startup sequence accordingly.
btw, try to boot to early startup and then with no s-s, with mouse buttons pressed, wanderer may need about 6mb to load.
other than that there may still be a bug in ata.device. last time i tried i had no problems to boot on an internal ide on an 1200, but on a4000 it was very flaky, and mostly remained stuck. perhaps its your problem. sorry for these messy comments, but i have not booted aros for a while, just from the top of my head.