you can't send objects with "page flag" enabled.  the easy way is to move it to the right of another object on the same page of the level.  if there isn't another object on that page you can disable the page flag but then the rest of the objects will shift a page

there's a document on how to use SMB util you should check it out it's got some useful stuff in there http://www.romhacking.net/docs/369/