Workaround:1) <esri:SimpleFillSymbol id="sfsHighlight" style="solid" color="0xFF0000" alpha="0.5"> <esri:outline> <esri:SimpleLineSymbol color="0xFF00FF" style="dash" width="2" /> </esri:outline> </esri:SimpleFillSymbol>If you change the SimpleLineSymbol style to "solid", the drawing will work fine (POLYGON as well as FREEHAND_POLYGON).2) Setting the Library Path (Properties->Flex Build Path->Library Path) to ArcGIS API for Flex version 1.0 library, the issue with the drawing doesn't persist.