isSensor not working at all

Shouldn’t this make the box pass through the platform?

local platform = display.newRect( 20, 200, 280, 15 )  
platform.myName = "platform1"  
physics.addBody(platform, "static", { density=1.0 })  
   
platform.isSensor = true  
  
   
local box = display.newRect( 20, 20, 50, 50 )  
box:setFillColor(255,255,0,255)  
box.myName = "box"  
physics.addBody(box, "dynamic", { density=1.0 , bounce=.7 })  
   
  
   
box.preCollision = onLocalPreCollision  
box:addEventListener( "preCollision", box )  

Also read the comment on this non-working example from the API docs:

http://developer.anscamobile.com/reference/index/bodyissensor

[import]uid: 21280 topic_id: 7512 reply_id: 307512[/import]

This seems to be fixed in Version 2011.268 [import]uid: 21280 topic_id: 7512 reply_id: 26639[/import]