diff --git a/examples/api/multi_filter.html b/examples/api/multi_filter.html
index 648d3213..3dc6d54c 100644
--- a/examples/api/multi_filter.html
+++ b/examples/api/multi_filter.html
@@ -22,8 +22,8 @@
 				} );
 				
 				$("tfoot input").keyup( function () {
-					/* Filter on the column (the index) of this element */
-					oTable.fnFilter( this.value, $("tfoot input").index(this) );
+					/* Filter on the column based on the index of this element's parent <th> */
+					oTable.fnFilter( this.value, $("tfoot th").index($(this).parent()) );
 				} );
 				
 				
diff --git a/media/js/jquery.dataTables.js b/media/js/jquery.dataTables.js
index 6eff7960..7929e458 100644
--- a/media/js/jquery.dataTables.js
+++ b/media/js/jquery.dataTables.js
@@ -296,23 +296,27 @@
 		
 		/* Check that the class assignment is correct for sorting */
 		if ( !oCol.bSortable ||
-			 ($.inArray('asc', oCol.asSorting) == -1 && $.inArray('desc', oCol.asSorting) == -1) )
+			($.inArray('asc', oCol.asSorting) == -1 && $.inArray('desc', oCol.asSorting) == -1) )
 		{
+			// either sorting is disabled for this column or neither 'asc' nor 'desc' is in the array
 			oCol.sSortingClass = oSettings.oClasses.sSortableNone;
 			oCol.sSortingClassJUI = "";
 		}
-		else if ( $.inArray('asc', oCol.asSorting) == -1 && $.inArray('desc', oCol.asSorting) == -1 )
+		else if ( $.inArray('asc', oCol.asSorting) != -1 && $.inArray('desc', oCol.asSorting) != -1 )
 		{
+			// both, 'asc' and 'desc' are in the array, so it can be sorted both directions
 			oCol.sSortingClass = oSettings.oClasses.sSortable;
 			oCol.sSortingClassJUI = oSettings.oClasses.sSortJUI;
 		}
 		else if ( $.inArray('asc', oCol.asSorting) != -1 && $.inArray('desc', oCol.asSorting) == -1 )
 		{
+			// 'asc' is in the array, while 'desc' is not, so the column can only be sorted ascending
 			oCol.sSortingClass = oSettings.oClasses.sSortableAsc;
 			oCol.sSortingClassJUI = oSettings.oClasses.sSortJUIAscAllowed;
 		}
 		else if ( $.inArray('asc', oCol.asSorting) == -1 && $.inArray('desc', oCol.asSorting) != -1 )
 		{
+			// 'asc' is not in the array, while 'desc' is, so the column can only be sorted descending
 			oCol.sSortingClass = oSettings.oClasses.sSortableDesc;
 			oCol.sSortingClassJUI = oSettings.oClasses.sSortJUIDescAllowed;
 		}
diff --git a/media/src/core/core.columns.js b/media/src/core/core.columns.js
index 5d4b3e67..6e7c9c78 100644
--- a/media/src/core/core.columns.js
+++ b/media/src/core/core.columns.js
@@ -1,5 +1,4 @@
 
-
 /**
  * Add a column to the list used for the table with default values
  *  @param {object} oSettings dataTables settings object
@@ -69,7 +68,7 @@ function _fnColumnOptions( oSettings, iCol, oOptions )
 		_fnCamelToHungarian( DataTable.defaults.column, oOptions );
 		
 		/* Backwards compatibility for mDataProp */
-		if ( oOptions.mDataProp && !oOptions.mData )
+		if ( oOptions.mDataProp !== undefined && !oOptions.mData )
 		{
 			oOptions.mData = oOptions.mDataProp;
 		}