Erm, are you sure, it is 28 ?
28 means the disk is write protected.
And BTW, you don't need to repartition the HDD. Just enable the "bootable" switch on your desired boot partition. No data will be lost.
If HDToolbox does not let you do this, you can try
ChangeBootPri.
Just enter: changebootpri dh0: boot
where "dh0" is the name of your partition.
Bye,
Thomas
