Sorry, I read this a couple of days ago but forgot to say thanks. I remember trying that script before and it getting intermittently disappearing meshes so I stopped using it. Whether it was the script or not is another matter. Cheers anyway!
Here is a link I found on Highend, a script called active smooth poly. I haven't tried it myself. http://www.highend3d.com/maya/downloads/mel_scripts/modeling/poly_tools/3304.html