I have a A500+ with the new ACA500plus and would like to prepare a 4gb CF and install games onto it.
I find it very strange why I don't see my CF in HDToolBox. It all worked before so I can't explain why it doesn't work anymore.
Have you set the controller as UAE or IDE? If UAE have you changed SCSI_DVICE_NAME from scsi.device to uaehf.device? To get there left click HDToolbox once (to select it) then go to Information in the menu or press Amiga+I key.