Aircraft track gone berserk

[Blackthorn]

I have had this happen only occaisionally but sometimes a route goes berserk,  see the image showing two diagonal the trail lines going wildly off track. Any ideas why?

[tarbat]

Purple rain - see http://www.airnavsystems.com/forum/index.php?topic=671
A common occurrence when aircraft avionics report the wrong position.

[Blackthorn]

Thanks Tarbat, thats explains everything.