At first I thought I used the hots editor so I am redoing my map this time I know I chose lotv and the same bug appeared. It's not that big of a deal but its annoying.
The movement speed number in-game is higher than what it should be but the units still move at the correct movement speed. This happens when you publish the map or go to "test document" (example, say if queen's normal movement speed is 1, I know its slower than 1 I just dont know the number, the movement speed number in-game it will show the number being higher, something like 1.9 but she still moves at 1).
The bug does not cause the units to move faster, its just a display issue.
Your example can be tricky. Zerg units have bonus on creep so you have to make sure there is no creep under the unit. I'm also not really sure about what you're experiencing as when I place a marine on an empty map and set its speed to 1, in-game it displays 1. There is no error. Do you have a specefic unit this happends with or more ideas what could be happening?