Ethereal Helms = Ral + Thul + Pefect Sapphire, for godly merc Dreams and Deleriums.
http://www.battle.net/diablo2exp/items/cube.shtmlThe thought reason for this glitch was because when you upgraded ethereal unique and rare armors, their ethereal bonus was lost. Meaning that they were ruined. However, now that 1.11 has fixed that, you can upgrade unique ethereal armors, shields, and helms. For example: I upgraded an ethereal 217% Shaftstop. It receive 2287 defence, rather than somewhere around 1400 like it would have received in 1.10. The cube glitch is a side effect of this fix, and Blizzard has yet to confirm/fix it. I hope they don't, though. My mercinary loves his Fortitude:
P.S. This glitch won't work on ethereal weapons.