That error would appear to be a privilege violation error which could mean there is code that is being attempted to run that is not compatible with the CPU. What filesystem is the boot partition of the IDE Hard Drive formatted as? If you can, attempt to create a boot floppy (ie Workbench or the Install floppy) and copy the 68060 library files to it and see how far you can boot with the IDE drive attached.
If you have no luck I suggest erasing the RDB from the IDE drive (after first copying any needed data from it if there is any) with another computer and starting over with HDToolBox from an Install disk.
With the memory, if there is any RAM on the A4000 motherboard, try taking a stick from there and using it on the card by itself to see what happens.
