Maybe I'm just lucky. Seen over 10 drop myself doing my farming thing- none drop when I was actually clearing the instances.

It's luck of the draw I guess. Got it on my very first kill in PoS once, and have gone for 5+hours without one drop. Never gone more than 5hrs though.

Like you said though most of us multiboxers have money to burn anyway I don't even farm anymore and the only heroics I loot anymore are ICC 5mans.