steps to reproduce

1. load the attached file with

   <spreadsheet id="ss" hflex="1" vflex="1"
   				showFormulabar="true" showContextMenu="true" showToolbar="true"
   				showSheetbar="true" maxVisibleRows="70" maxVisibleColumns="4"
   				src="/WEB-INF/books/dropdown-lastcolumn.xlsx" />
   

actual result

dropdown doesn't show in column D

debug info

• the button is hidden by css overflow of its parent DOM