Hines, M.L. and Carnevale, N.T.
NEURON: a tool for neuroscientists.
The Neuroscientist 7:123-135, 2001.
(an excellent paper, by the way--have you read it?) and found that the value of Ra given in the legend of Figure 2 (180 ohm cm) produced a DC length constant shorter than the 500 um that we reported in the paper. A little arithmetic was all that it took to show that the correct value was 160 ohm cm. Then I checked the source code of the model that was used to generate the related figures in the paper, and confirmed that Ra = 160 ohm cm was correct. It took me a few more minutes to make the necessary change to the old OpenOffice file, and put a revised pdf on the WWW site.
The point is that this particular model was extremely simple--just a passive cylinder with spatially uniform properties of membrane and cytoplasm--so it was easy to detect and fix the incorrect parameter value. But almost all comp neurosci papers published these days involve models with complex anatomy and biophysics, and multiple parameters that may have spatially inhomogeneous values. Think of all the opportunities for typographical errors, and how important it is for authors, in the interest of scientific reproducibility, to make their model source code available in publically searchable databases!