RROD is in almost all cases a cold solder joint under the gpu caused by flexing of the mobo,uneven standoffs,leadfree solder and heat.Usually a good,even reflow with flux fixes 90% of rrod for a good while,specially if a hybrid fix is applied afterwards to keep even pressure on the gpu and keep the mobo flat.A fanmod to keep it cooler and prevent flexing increases longevity as well.Most of them run from 6 Month if you`re unlucky to another 1-3years.I fix Xbox360s every day for a living

A re-ball lasts longer because the leadfree solder is replaced with better,more flexible and less porous leaded solder.
Its a hell of a job though to replace the ~1000 0.6mm diameter solderballs,you`ll need a good rework station,a reballing jig,boardholder,flux... and (much) more than one Scrapbox

mod please delete sorry didnt mean to doublepost
This post has been edited by oedi103: May 30 2011, 12:31 PM