i had the same thing happen to me but it went away as my liver became healthier, through not eating meat for a while. i couldnt keep the mean or the lecithin down for some reason.
i tried sunflower lecithin as well and it did the same thing. so i figured my blood was too fatty to detox the added fat of the lecithin or the ability of it to emulsify fat. maybe go on a low saturated fat diet for a month or so and try it again
it was weird too cause my body loves the taste and craves lecithin so i was happy when i could take it easily