My eight year old son has similar vomiting patterns. We too are going to see a neurologist. What did you find out?
I saw a great program (sorry, but I forgot what station) anyway, it was titled Medical Mysteries. It was about a 6 year old girl who would vomit every night in her sleep (she had no recollection of it the next day). She was eventually diagnosed with a seizure disorder, which medication took care of, and the vomitting stopped. I'm glad you will be seeing a neurologist. I hope you can see him sooner than later.