First of all: Never ever use more than one instance of jQuery on the same page. You are using versions 1.3.2 and 1.6.4 together, which will create problems.
Second: You use the global "var current" several times. Each one overwrites the previous one in that case.
Despite this, when I add two new Ingredient areas and fill out number 3 for example, I can see from the POST request that it was correctly sent as ingredient3. So I don't see the problem