I realized exactly whats going on here. Its related to another issue I posted (but can't find). The problem is that when a row is added, it propagates the information from the first row. In other words, its as if the new row button is using the first row as a template.. So, when creating a new invoice, one adds a new row, and its blank. This prompts the user to select an "item" and this action updates the "tax" and "unit price" fields. Now, on the other hand. When editing a saved invoice. Adding a new row, now is generated with the first row's information. Thus the user needs to delete the description and switch away from the item to another item and then back, for tax and "unit price" to fill out. Also, if SI is not setup with multiple items, it won't ever update:-(
