2.0.7 F ,
that depends on how many options you have set in your shop.
* Australian stores do not need tax rules.
* The shop does not have complicated - dropdown variants of related items - If you just buy and sell individual items without keeping stock. ( no issues)
* but is you are trying multiple - variants , keeping exact stock and have taxes for country and state , federal and shipping then yes it may have afew bugs.
Simple shop - no issues.
Again I have no shopper groups set and the state tax works perfectly - ( but in Australia we have no state taxes)
* at this present time - after updating to F I have an issue with the default shopper - after he logs into the shop.
There is no issue with a guest - I have reported this elsewhere.
http://forum.virtuemart.net/index.php?topic=104036.0