Currently I have two websites that almost identical in set up.

However, only one doesn't display or tally the Sales tax properly: Example:
Sub-Total: $38.76
United States Postal Service (1 x 4.00lbs) (Parcel Post (4 - 7 days)):$6.05
Sales Tax:$0.00
Total:$44.81

My settings are the following in MyStore Admin:

Tax Decimal Places: 2
Display Prices with tax: True
Display Prices with Tax in Admin: False
Basis of Product Tax: Shipping
Basis of Shipping Tax: Shipping
Sales Tax Display Status: 1

I have only one Tax zone: Nevada 8.1%

Please assist, as I am unable to find the solution after even comparing both sites.

Thank you in advance.