TA Beta 5 Terror Stars

I think this is a bug.  I am playing on Normal difficulty, large map, using the Terrans.  I can build a terror star without problems.  After I use the terror star I am not able to move it.  When I save the game and load it again, I can then move the terror star.  Is this a bug?  This will be the first time I have reported anything so I'm not quite sure who this works.