Dropdownlist in DataGrid - strange side effect

Question

I am implementing a dropdownlist as a custom renderer in the Spark DataGrid. The following code will create a negative side effect: When I drop the control down to select an item it will take two clicks for the control to close and show the selected item. Here is the code:
private function onDataChange(event:Event):void
               Grid(owner).selectedItem[column.dataField] = selectedItem[column.dataField];
Any idea what that might be?
Thanks

Answer 1

In stepping through the code I think I have identified where the problem is, but don't have a solution. It seems that the default preallocation size is being used, rather than taking the value configured in the TopLink mapping file. When I set the preallocation size in the Java code at runtime the problem goes away.
But, this only provides me with a work-around. I would like to have TopLink read the mapping file and use what has been configured. Here is a snippet of my code for setting up the TopLink connections:
     login = new DatabaseLogin();
     DataSource dataSource = // get the configured datasource
     Connector connector = new JNDIConnector(dataSource);
     login.setConnector(connector);
     login.usePlatform(new Oracle10Platform());
     login.useNativeSQL();
     login.useNativeSequencing();
     // Would like to avoid doing the following
     //login.getDefaultSequence().setPreallocationSize(5);