Hi,
I haven't tested this yet, but I believe you should have an extra carriage return. Also, throw a regen in there, so the drawing database gets updated. I've seen some strange results if you don't regen, but it is optional.
;start
_explode
ALL
regen
_explode
ALL
regen
_explode
ALL
;end
As for the dialog box that pops up... seems in some commands in AutoCAD it is smart enough to see you are running it from a script and suppresses the dialog boxes itself (just for programs such as Hurricane)
Let me know if the above worked better for you!
Regards