[edit] Missed the fact that the post #83 I was referring to is in an old thread from 2004. Ooops!
Looking at that post #83 here
http://www.pprune.org/rotorheads/189945-ec135-5.html again, the comment in there about 71kg unusable fuel reducing to 7.5kg above 80kts caught my eye. Does that mean that in decelerating below 80kts that any such fuel becomes unusable again?
Also, post #83 says "When operating at different speeds with low fuel quantity between hover and cruise the FUEL PUMP lights will come on and off which is normal and also depends on the location of the C of G." So, with fuel quantity captions illuminating and going out as part of expected behaviour does that mean that a pilot could be tricked into thinking that any warnings are transient when in fact they are alerting him to a fuel state that requires more careful management?