Lockups, finally solved.
Moving to x86 archlinux didn’t fix the lockups I was experiencing when upgrading to hardy either. So after some more frustration and irritation I decided to compile the 2.6.23 kernel (was tricky somewhat because of the upgrade to gcc 4.3).
And now after a few days, I hope, I can say that the lockups are finally gone.
I hope it is fixed soon.