[Closed] SetUserProp problem

Hi there people.

below is a part of my code :

local i = 1
				for li in lv_objects.listitems do ( -- find selected item
					if li.selected == true then (
						--obj = (execute("$'"+li.text+"'"))		
						obj = getNodeByName li.text
						if obj != undefined do (
							setUserProp obj "Uid" val
						)
						si[si.count+1] = i
					)
					i=i+1
				)	

However for some odd reason not all objects are changed. and i have no idea why.
The objects that are changed are always changed. those who are not change never change.
all objects are simple mesh objects…???

ps: both ways of seeting obj work. but the same problem… ???
using : 3dsmax VIZ 2008