Yes, that's an oldie - it was already in the original Elemental: War of Magic release.
Saving and loading clears the "moving" status and allows the turn to end - but it may effectively cost you one turn (another oldie).
@venegeance88: Search the map for a "running" unit - one that tries to move into a square that it cannot enter. See the OP for one example of such a situation. I guess you have some friendly "obstacle" at a choke point, and every few turns one of your units gets stuck there - once you know where it is, you can easily check it if the turn doesn't end.
@parrotmath: Given the age of the bug, I'd not hold my breath for a fix even with a clear description of when and how the bug happens (several have been posted already), a save game, a debug err (I think both have been posted as well), and even more, e.g. a youtube video showing the problem.