I experimented and moved the coupon code to after the taxes and all worked as expected.

See text checkout summary:

Sub-Total : $32.85
Free Shipping Options (Free USPS First-Class Mail (Domestic or International)): $0.00
Local sales tax:$2.13
98271-8848 Local Tax 2.10%: $0.69
Discount Coupon: JMMCYBER20 : -$20.00
Total : $13.95

Is it better to give discount pre-tax or after tax? Example... lets say it was a % discount.

Hmmm... I will go this way for now. Less phone calls!