No method calls to org.compiere.model.Tax are transaction aware. This causes problems when many things are done automatically.
For instance creating a customer/location and order in the same transaction will not work since the newly created customer is not yet visible to the tax selection in the Tax.class used by the order lines.
Updated priority on this one since it causes problems everytime anyone programmatically tries to create an order or any other document with taxes within a transaction.
I fixed it in my own repository and linked to it in a comment.
I reopen this issue because the "Resolved" state means that this issue is solved in main iDempiere trunk. For this reason this issue can be forgotten if we set it to Resolved.
The right status for this is "Peer Review" so it will be on Carlos review list.
Sorry I forgot about the state-rules. Thanks for changing