Incompatible cpu error message, cpu meets specifications !

[onestory151]

I have an hp touchsmart pc desktop 300-1025, the motherboard is an app78-cf jesse and i am attempting a processor upgrade.

I get an "incompatible cpu" error message at startup on a processor that meets the motherboard specifications precisely.

This is the processor that doesn't work;
amd cpu athlon ii x4 605e 45w am3 2mb 2300mhz retail amd ad605ehdgmbox

whereas this one did work;
amd cpu athlon ii x4 605e 45w am3 2mb 2300mhz retail [ad605ehdgibox]

i don't have access to the second processor now and am in posession of the first, can anyone suggest any solution
or shed any light on what the issue might be ?

Thank you