Thanks for your suggestion, Dave. I will look into that. You can download the winds by tapping on the button with a cloud and then going to Download Winds.
I also encourage you to have a look at the manual, if you have not done it already:
http://igoapp.ca/resources/Files/igodispatch_saab340_manual_pad_v3.0.1.pdf
The culprit for not finding KTVL could be due to an issue with navdata. The manual explains the proper way to update it.
Cheers,
Igor