Ok, I think we have a bit of confusion here. The invoicing address has never worked correctly. Before I modified anything, the State/Province section would always be blank. Even when I force someone to use an invoicing address, it was impossible to select anything in that drop down. That is why I modified the edit.front.invoice.xml file, to get the two fields to "sycn". Here is the post where I found that information www.joomlapolis.com/forum/88-general-usage/140437-solved-state-dropdown

I changed my edit.front.invoice.xml back to it's original state, still, same problem. I even unpublished the CB state/country entries under Field management, created a new dropdown field (named it state2) with only WV as the field value. I changed on the CBSUBS>SETTINGS>DISPLAY>INVOICES tab to use "state2" on the invoice. Still, the same problem, nothing shows up in the State/Province drop down on the Invoicing Address nor does it know what state I have selected from registration.

Now, I have managed to reproduce getting it to show up again though (I had mentioned in my first post that I was able to get the states to show up once and the tax worked). To get that drop down to work, you have to click "save" on the invoicing address page (I had it set up for non-manditory invoice addressing), then go back and edit the invoicing address again and THEN the states show up. This is the ONLY way it has ever worked. And yes, once I select West Virginia as the state, save it, THEN the tax gets applied.

Needless to say, I'm a bit confused

Update: Also, changing from the default country of "United States" to another country and back again shows the States listed under "States/Provinces". Still, I need this to pull the data from the registration form.

I've also added joomla debug from the initial invoicing page.

I have re-installed the main joomla CBsubs plugins, as well as the CB plugins (under the CB Plugin installation). Same issue. I did notice, however, before I had installed the CBPLugins (cbtax and others) when I went to register, it actually wanted me to choose a default country and was not pre-selected for the USA. But, in the end, this did not fix the problem. So it's ready to go whenever you need test again.