If remembered well, from Precise Beta1, the evil was inside of Precise system especially on dmraid disk-managements... X(
So in fact I had to roll-back to Oneiric. Actually Precise couldn't handle dmraid initializations within boot sequence, you know. But today I could confirm this workaround for it:
Yeah this did a trick !! :) Wow !
Then I could run precise on Sony VAIO Z21 again today...
It's crazy, you know... Yep, it's the only "Air" to be able to beat any other hi-end desktops built like a tank. :)
If you guys want anything for perfoemance on linux mobile, let's do "Z"...