I know how you feel!
My daughter never spit up as a small baby - not even a normal amount - then when she turned 1 year old, several things happened at once... she got the chickenpox vaccine which gave her a very mild case of chickenpox and she contracted the flu (this was all Jan 2007) and began vomiting. But the vomiting never stopped even after the flu was over - and it continued after each and every meal for 4 months!!! When we finally did go to see a pediatric specialist (we had to wait for about 8 weeks for the appt!), she said that our little girl was suffering from 2 things - allergies that were causing her stomach to swim in mucus, making it volatile and queasy, and second a condition called "Post viral gastric pyloris (sp?)" which is to say that after the flu and chicken pox, her stomach muscles, which are supposed to move the food from her stomach to her bowels, stopped working (as they do during a virus) and never started back up again (at least not at a decent enough pace to keep things from getting backed up). And so every time she ate, everything would "hit a wall" and be pushed back out...
In the end, there was not a great deal that we could do in terms of treatment really, we just had to wait it out, and over the next month or so it did slowly stop due to starting an allergy med (singulair) and just the natural progression of the PVGP. The doctor said some people (this is a condition that affects adults as well as children) suffer with it for up to 18 months - and there's no way of preventing it or being able to tell who it will happen to - just luck of the draw and you roll the dice every time you get a virus.
I don't know if this has anything to do with your daughter - but it may give you a place to start - especially if she is also experiencing alot of allergy symptoms. Good Luck!