Tuning page can save zero-values ?

please see http://diydrones.com/forum/topics/wpnav-parameters-changed-to-0-after-autotune
maybe there should be some logic that prevented parameters from being written unless all are populated/read before ?

Start with the Tuning page and review how parameters are read and saved, using the linked report about WPNAV parameters changing to zero after autotune as the reproduction context. Confirm whether incomplete or unread parameters can be written, and consider the issue done when valid values are preserved instead of being saved as zero.

Written by the indexing model from the issue text.