If Star Wars has taught us anything, its that sometimes you just have to turn off your targeting computer and go with what you know to be true.
Your computer is only as good as the programmer who set it up. The information could be off, or the processing of said information could be bugged. In general, its all good. But when it really matters, you need to look past the programming, open your eyes, and see whats actually in front of you.
When the instruction manual is over 1000 years old, you shouldn't put much reliance on it either. You can't program your Blu-Ray player using a VCR manual.
http://goo.gl/2VyCo