I've got the same problem with my push mail setup, i can't seem to find any push notification in relates to the Gmail or facebook, all of which my iphone did for me.
Does it have to do with the carrier? i don't really think so....how am i be able to get my gmail pushed in?
I am running my Gmail in the background at all times and still nothing. A bit upset about the fact that i need to check and refresh all the time to make sure i don't miss out any mail