It could be possible, that the units (floortrap) are irregularly sized, and cannot move to a certain location. (i.e, a landed cc cannot take the spot of a marine confined within a 1x1 pathable location) although that example is obvious...
Try using that trigger moving the trap to an obviously movable location.
Or, try allowing for the trigger to "wait" (add a wait command approx. 50ms or less) then moving the unit; because at times, the trigger occurs so quickly that it causes the game to "think" that the unit cannot be moved there, even though theres room for it to move to the new location.
If all else fails, traps cannot be moved (as you have stated).
(Why would you use a trap anyway? uniqueness?)
Try placing the traps in each spot abled to be placed, and putting the traps under a computer player in the editor, then when the player fulfills a certain condition in the game, give the trap to the player at that location... thats the closest you could get if you do indeed find out that traps cannot be moved.
QUOTE
Can you create missile traps with triggers?
If so than remove the turret and use create missile trap etc.
No, you cannot. A trap is not necessarily a "real" unit in the eyes of the program "StarCraft". It was a unit that happened to be in the program, that had been disabled by the makers for reasons which I cannot determine. Most of the units that are "disabled" are usually owned by p13 or 14. The special editors such as scxe, scmd or sf happed to "find" these 'hidden' units, thus allowing for the placement of them. But, this is an external program that does not coinside with the actual program. Thus allowing for "illegal" placement of these units outside the game. StarCraft was not designed to create these "illegal", 'hidden', "unreal", disabled units ingame. If you could, there would be little point in posting this topic.
Side Note: Hey rexy, thats a very cute cat you got in your picture thingy

.