lol Jimmy I agree with a lot of what Vic contributes here and respect what he stands for, even if he does give me the odd whack to knock me of my perch ;D ;D ;D
Try to get your pigeons to eat hulled Sunflower seeds, you can buy these in health food shops. Peanuts are good but I find the pigeons will turn their noses up at others grains if fed in quantities.
Paulo what you've described, pigeons acting strange/nervous & spewing up grub is classical behaviour of the onset of Y.B.S. Lock them up for the remainder of the day, feed as normal and check their crops/droppings first thing in the morning.