Error when trying to group selection

I am having a problem with InDesign CS4 grouping objects I have the applescript select. The following code gives me an error: Adobe InDesign CS4 got an error: Invalid parameter. However, when I select the objects manually and run the same code, it works fine. Any suggestions?

 	

tell active document

		select (every item of all page items of page 1 where item 1 of its geometric bounds is greater than page1x2 and item 1 of its geometric bounds is less than page1y2 and item 2 of its geometric bounds is greater than page1y1 and item 2 of its geometric bounds is less than page1X1)

		set myDuplicateSelection to selection

		set myGroup to make group with properties {group items:myDuplicateSelection}

	        set duplicateMe to selection
		
		
		
end tell

Hi. You didn’t disclose your variables’ actual values, but I’ll assume what they are based on their names; they appear to describe a fairly small region at the page bottom, and it’s possible your items don’t live there. Geometric bounds’ order is {Y1, X1, Y2, X2}.