There was also this one in 2003:
http://www.bst-tsb.gc.ca/eng/rapports-reports/aviation/2003/a03w0194/a03w0194.asp
" Fuel unporting is a phenomenon whereby fuel flows away from the fuel pick up in the fuel tank, and will result in a power loss or engine failure due to fuel starvation. Unporting is a function of the amount of fuel available (usually very small quantities), the attitude of the helicopter, and sloshing of the fuel in the tank."