Kolossi, you make the point that everyone should contribute from their field, within their realm of competence, and I agree with you. However many of the posts on this thread completely discount the design expertise of the aircraft manufacturer and the skill and experience of the pilots who operate the aircraft and the engineers that maintain them. That to me is unwise.
By way of example, while I now have to admit that Occams razor suggests that fuel system design or the fuel itself is the culprit, the "water in the fuel" crowd do not appear to know that fuel quality is monitored daily and that the petroleum industry has been paranoid about jet fuel quality, especially water contamination, since at least 1980. Before the fuel reached the aircraft, it will have passed at a minimum three filter/coalescer units designed to remove any water or particulate contamination.
Similarly Boeing would be well aware of the risk and catered for it in its design, so how someone can blandly say on page one or page two of a thread "it's water contamination" is beyond me.
The same goes for RF interference. Do the proponents of this theory think Boeing has never heard of it, nor allowed for it's in it's detailed designs? Same for pump cavitation theorists, do you think the engine designers are idiots?
That's why people get irritated by some posters - because their helpful suggestions imply that the designers, pilots or maintainers of the aircraft were idiots.