syntax error when pkg install io-xxx.tar.gz package

I have just build Octave 3.0.1 from source in Kubuntu hardy.
And when I tried to install the io-xxx.tar.gz package, I got this error

octave:2> pkg install io-1.0.5.tar.gz
parse error:

  syntax error

>>> pkg install io-1.0.5.tar.gz
                   ^

Does anyone else experience this problem? any solution?

I didn't have problem when I switch back to 3.0.0