Restoring purchases made with In App Billing How can I switch the Play Account used for in-app billing?

No matter which account I "activate" in the Market app, all in-app purchases only go through the first account which is contrary to the experience when purchasing normal apps.

When purchasing normal apps, the billed account is the one that was active in the Market app at the time of purchase.

This causes a problem as I am also unable to restore my in-app purchases unless the account that made the purchases is the primary account on the device.
I asked Google. This was their response.


  Thanks for writing in. I understand you would like to know how to
  choose what account in app purchases are billed to. I apologize for
  any frustration this has caused. When you go to make an in app
  purchase the purchase is going to be billed to what ever account was
  used to download the app the purchase is going through.