Question about CVPal Lock Bits

I was trying to program a CVPal and always got the same error…then I studied the Lock Bits in the Attiny84…as per Firmware instructions…

avrdude -V -p t84 -c PROGRAMMER_NAME -P usb -B 10 -e -u \
		-U efuse:w:0xff:m \
		-U hfuse:w:0xd6:m \
		-U lfuse:w:0xde:m \
		-U lock:w:0x2f:m
avrdude -V -p t84 -c PROGRAMMER_NAME -P usb -B 1 -U flash:w:cvpal.hex:i -U lock:w:0x2f:m

But I always got the same error when trying to write the Lock Bits
Attiny84 should only have 2 lock bits (LB1 and LB2)…and values could be only 4:

0xff, 0xFE, 0xFD, 0xFC…

why is it set to 0x2F then?? 0x2F doesn’t even seem to be a valid value for the Lock Bits…
Or am I missing something?

I mean, these are the 4 available values for Lock Bits on the Attiny84…
But maybe I am missing somethin very basic…