A bit of a delay - I've been trying to trace the problem - but answering your questions:
I'm using the built-in GPS for location. This appears to be one of the problems since whilst other apps such as Google Maps register a change in location Tasker sometimes doesn't. This seems to stem from the 50m / 100m / 200m radii options that do not appear to be very precise.
The firmware is Android 4.4.2 - This is the version the phone came with when I bought it about two months ago. The problems only seemed to start after the latest Tasker update.
Thank you for the tip about the Run Log option. I did not know it existed and it is just what I needed to check what is going on. As well as the unreliability with the GPS switch, the other problem is that the Mobile Data toggle does to always work even when other Tasks in the same Profile do. I have yet to find a pattern in this and it appears to be fairly random.
As a said before, this problem only seems to have arisen since the last Tasker update.
Thank you for the tip about the Run Log option. I did not know it existed and it is just what I needed to check what is going on.
>As a said before, this problem only seems to have arisen since the last Tasker update.
Try also disabling (in Tasker) Prefs / Monitor / Use Motion Detection if it's visible.
Pent