The message seems to have gotten sent since it's in my Sent folder rather than the Outbox. Fluke? Something going on on your end? Hopefully it's a one-time event. Sending fuel-ups via text messages is pretty convenient.
No, the extra entry due to my going to the website and adding the fuel-up manually (after it failed to work and before my post here), followed by testing it again due to your suggestion when it worked.