Eddy, I have not heard of that one. Then again, that doesn't surprise me.
The whole "isolated ground" theme is filled with all sorts of mystical theories and majic potions. The 'geek' types seem particularily imaginative in their explanations.
Personally, what I think is going on is this: Advances in technology allow us to notice things we never did, and bad practices are catching up with us.
IBM seemed to lead the pack with the 'isolated ground' nonsense. Since then, they've backed off considerably. I think what is needed, mainly by electronic components, is a good, low impedance ground path. Properly made up pipe ought to be sufficient.
In the real world, though, fittings are loose, locknuts are loose, etc. So, in the end, running a green wire straight from a critical component straight to the panel can be cheap 'insurance.' If nothing else, you've eliminated one cause of problems.
The same thing goes for separate neutrals. In a flash, you completely eliminate one cause of power quality problems (loose neutrals), and counter one effect of harmonic problems (excess current on the neutral).
Likewise, the use of steel pipe has been shown to eliminate EMF issues.
I realise that a lot of these problems would also be eliminated if the related trades did their jobs correctly; data problems can be quite interesting when the cables are draped over the fluorescent lights!
Ironically, though, most of these "new fixes" are nothing more than a return to older, prooven methods... and avoidance of clever little "handyman short-cuts."
