Just a FYI
I ran into a problem tonight that when I used a "-" in a product variation name and the product was purchased the field did not make it across from Google Checkout to e-junkie even when the variation was not selected.
In my example I have a yearbook listed with the two variables, student name (text) and grade level (drop down, pre-k, kindergarted, 1st, etc...).
When I had "Pre-K" as a variable when a yearbook was purchased only the student name was making it to Google Checkout and e-junkie. I removed the "-" and it fixed the problem.