Moving on from Nutty's thread about eating food on a play date, does anyone remember one of the Robert Winston programmes where he talked about fussy eaters and "super tasters". He did this test where people (incl their children I think) were given a piece of paper impregnated with a really bitter/salty tasting substance. I think without exception, the so called "fussy eaters" reacted strongly to this substance and the ones who will shovel anything down did not react at all. I'm not sure if they knew exactly what the test was about.
Anyway, my long winded point is that a fussy child may not actually be fussy at all but is more sensitive to taste than a non fussy child. They would also be more reluctant to try things since so many tastes would be strong to them that they'd get put off new things very easily.