Octave band filtering problem

Hey,

I'm doing some octave-band filtering for a project, and I got code from http://www.mathworks.com/help/dsp/examples/octave-band-and-fractional-octave-band-filters.html and it works fine on my desktop Mac (running Matlab 2009b). But I've ported it to a laptop I need for an experiment, and the basic code is giving an error as if it's never heard of this. Here's the basic example:

bandsPerOctave = 1; 
filterOrder = 2;
F0 = 1000;
Fs = 48000;
indexBand =1;

f = fdesign.octave(bandsPerOctave,'Class 1','N,F0',filterOrder,F0,Fs);
F0 = validfrequencies(f);
f.F0 = F0(indexBand);
Hd(indexBand) = design(f,'butter');

% On my laptop, this gives the following error:

??? Error using ==> fdesign.abstracttype.butter at 17
Undefined function or variable 'fdfmethod.butteroctave'.
Error in ==> fdesign.abstracttype.superdesign at 106
            Hd = feval(method, this, varargin{:});
Error in ==> fdesign.abstracttype.design at 11
    varargout{1} = superdesign(this, varargin{:});
Error in ==> errorTestingScript at 13
Hd(indexBand) = design(f,'butter');

It seems like something basic is wrong in the signal processing toolbox. This error occurs on the laptop whether I'm running Matlab 2010a or 2012a. Does anyone have any idea what's happening here?

Thanks so much!