uuum, ya said it didn't show up, thus: ya wan't it to show...
but now ya don't want it to show
;D
oh well, try this :
"MarkerName" setMarkerType "Arrow"
Just use the "Set marker type" command in a trigger/wp. Type may be any of:
"Flag", "Flag1", "Dot", "Destroy", "Start", "End", "Warning",
"Join", "Pickup", "Unknown", "Marker", "Arrow"