It's important to follow these instructions when transferring files from your PC to your Kobo device:
This section explains how to create waypoints and tasks on the go in XCSoar, without the need of importing the task or waypoints from outside.
Pan on the map and place the cross-hair where you want a waypoint to be created by tapping 'Display' -> 'Pan On' -> Tap and hold around the map
Tap 'Nav' -> 'Nav 2/2' -> 'Drop Mark'
Tap on the marker created -> select the marker from the list -> Tap 'Details'
Way-point menu appears. Tap on either of the arrows to move to next screen -> Tap 'Edit' -> Change the fields as needed -> Tap 'Ok' (now you have a way-point)
Go back to Way-point menu and tap 'Insert in Task' (if this is the first way-point you inserted in the task, you'll see a 'Created Goto Task' dialog