Buggy Problem: Fields Repeating

I'm building a fairly long multi-page form* and I'm finding that the longer the form gets, the more buggy GF is acting. It may be the install, I updated a couple of days ago but am trying to backup right now & re-install GF. I'm supposed to deliver this form tomorrow. :(
The biggest hassle I'm having with it is fields are repeating themselves and I don't know why. I am entering several products into an order form. A few days ago, I put empty product fields in as placeholders and tried to build the structure. I was going to quickly go in tonight and fill them all out. The problem is, when I fill one field out, its data (price, product name) is carrying to the next product field. Then that residual data over-rides whatever I typed into the second product once I update the form. So for example, instead of having five unique products, once I update, I get two products, each one repeated once or twice. This is happening throughout the order form.
The fields are repeating the Field ID #s, but I don't know why. Would this happen if I used the "Duplicate" function? But I'm pretty sure that's not how I built it. Is there a way to manually change the Field ID #s on each field so they stop repeating their data?
I also find that I have to update this form a lot, or risk having GF freeze up and not update, and lose the changes. This is becoming a lot more time-consuming than I would have liked.
*I did not want to build such a long multi-page form, but was not able to get my earlier question resolved where I was hoping to work with several small forms & find a way to combine their totals in a final form & send to Paypal via the PP Add-On.