maps.c:clip2d() function clips lines that are completely visible. This can be most easily seen in the draw_vector_ll() function by enabling the "Line not visible" printf, then while in UTM coordinate mode zoom out beyond world view (might have to shrink the window vertically go see this).
Logged In: YES
user_id=448632
Originator: YES
Also enable the next printf in order to see which vectors aren't getting drawn.
This problem may be the result of the corners of the view getting weird values when we're beyond the complete earth view.
The Xastir project no longer uses sourceforge for issue tracking and I am closing all open issues (all of which are very old).
If this issue is still important, please open a new one on https://github.com/Xastir/Xastir.