Following discussions on the dev list today, tweak the logic for sizing the HSSFCells array on a HSSFRow to reduce memory over allocation in many use cases (now cribbed from the size of the row, and uses the ArrayList growth metric)
poi/trunk/src/documentation/content/xdocs/status.xml
poi/trunk/src/java/org/apache/poi/hssf/usermodel/HSSFRow.java