It's the simple things that often catch people out Tinstaafl. Last minute charter has come in, pushing last light, boss and client are both getting impatient so you grab the aircraft, bundle your passengers aboard and get going deciding "Stuff the checklist, I'm in a hurry and I've done this a hundred times!" Only to feel that wretched sinking feeling in your stomach as you get 50ft above the ground, the engines start coughing and you realise you forgot to change back to mains after doing a X-Feed check!!
Just out of curiosity and I promise I'm not trying to cast doubts or blame or anything just purely curious. If an aircraft is known to have problems with Takeoff And/or Landing on the Aux Tanks, for example the climb/descent attitude causes the fuel lines to become uncovered, and the refueller has added the fuel that was meant to go to your Mains into your Aux instead so therefore the required fuel is now solely located in your Aux with your Mains being just about bone dry and you go to take off and have an engine failure due to the Mains being empty and the Aux being full, would the ATSB consider that Fuel Starvation because you had adequate fuel but just not in the selected tank or Fuel Exhaustion because the fuel you had in the Aux wouldn't have been useable for the Takeoff anyway?