I'm very confused. I'm having difficulty traveling to most of the planets in my game, it says that they are a distance of 9-10 parsecs away when I try to move my ships to them. When I press f9 to check, however, it will say the distance is 5 parsecs. Am I missing something? Is it just a glitch?

In case you're trying to move a ship from some system than are not colonized by you in a direction away from your closest colony its all right: as your maximum range is measured from a closest colony/outpost; so if your closest colony is on system A, and you trying to fly from some system B to some system C, thats possible that C will be out of range of A (say in 9-10 parsecs), while distance of B to C is only 5 parsecs.

In case its something else is bug sure; while map actually have a buggy calculations there are about 1 parsec discrepancy, not that much; this one would be new.