My guess is that it started to overwrite the maps and was then stuck. If true that's just shitty programming. Programming 101 - download stuff to scratch and only copy over the working stuff when you know it's good.
Sounds about right, but it's a tricky problem. If an app can only run a download when it's active you will forever be in that situation. TT tends to upgrade the app as a whole, which creates a different pain in the neck in that you need to have at least that amount of space free or the update will fail (and it takes the better part of a century to download).
It also has map updates, but I will have to talk to the Information Commissioner about TT forcing "sharing" before you are entitled to download their updates. I much rather pay and not share than being forced to share. In my experience, "free" never is, and I prefer to know the true cost of things.
Biting the hand that feeds IT
