I have a burrowed zergling following a ghost , but the sometime de zergling just get stuck in a corner and wont move again ...
anyone know why it get stuck , or what to do to avoid it ? or simply a suggestion to unstuck it?

Do you have multiple ghosts? Also, post a text message after it teleports so you can see if the trigger is still running or not.
We can't really help you more until you post your triggers, and give us more information, please do.
Its possible that if you are only teleporting the burrowed zergling from the location centered on the ghost, to the location centered on the ghost, then the trigger occasionally hangs for a second, and the zergling is no longer within the location around the ghost, so it is no longer teleported to be below the ghost.
yes , this is exactly what i am doing , is there a way i can restart the trigger when it stuck?
Just change it so that the zergling goes to the ghost no matter where the location on the ghost is in so just make it "anywhere".
what would be the trigger ? i cant realy figgure it sry

Replace the location to teleport the zergling from with anywhere, or another, larger location that centers on the ghost.
A simple version would look something like this, although you may want to only reteleport the ling once it has left the ghost location, as to reduce lag from constantly teleporting a burrowed unit under a ground unit.
Conditions:
Always
Actions: Move all zerg zergling at anywhere to ghost
Preserve trigger
And for teleporting only when ling leaves ghost location:
Current player brings at most 0 zergling to ghost.
================================
Center location ghost on ghost owned by current player at anywhere.
Move all zergling owned by current player at anywhere to ghost.
Preserve.