Cannot erase AVR

I have been trying to update the firmware on my techzone monotronics board without much success so I have now plugged a AVR programmer in, bypassing any possible boot loader issues. What I am finding however is that I still cannot program the device properly and still cannot erase it.
from AVR studio 4 I am pressing the button to erase the chip, it just says:

Quote

Entering programming mode.. OK!
Erasing device.. OK!
Leaving programming mode.. OK!

I then do a read, but the resulting file is not all FF, it is still programed, infact the firmware still runs!
how can this be?