diff --git a/js/jquery.tablesorter.js b/js/jquery.tablesorter.js
index fe53b5f5..247b459a 100644
--- a/js/jquery.tablesorter.js
+++ b/js/jquery.tablesorter.js
@@ -255,7 +255,7 @@
 								v = parsers[j].format(t, table, c[0].cells[j], j);
 								cols.push(v);
 								if ((parsers[j].type || '').toLowerCase() === "numeric") {
-									colMax[j] = Math.max(Math.abs(v), colMax[j] || 0); // determine column max value (ignore sign)
+									colMax[j] = Math.max(Math.abs(v) || 0, colMax[j] || 0); // determine column max value (ignore sign)
 								}
 							}
 							cols.push(tc.cache[k].normalized.length); // add position for rowCache
@@ -690,7 +690,7 @@
 						.bind('selectstart', false)
 						.css({
 							'user-select': 'none',
-							'MozUserSelect': 'none'
+							'MozUserSelect': 'none' // not needed for jQuery 1.8+
 						});
 				}
 				// apply easy methods that trigger bound events
@@ -769,6 +769,7 @@
 					updateHeaderSortCount(table, list);
 					// set css for headers
 					setHeadersCss(table);
+					$this.trigger("sortBegin", this);
 					// sort the table and append it to the dom
 					multisort(table);
 					appendToTable(table, init);
@@ -1293,7 +1294,8 @@
 			return ts.isDigit(s);
 		},
 		format: function(s, table) {
-			return s ? ts.formatFloat(s.replace(/[^\w,. \-()]/g, ""), table) : s;
+			var n = ts.formatFloat((s || '').replace(/[^\w,. \-()]/g, ""), table);
+			return s && typeof n === 'number' ? n : s ? $.trim( s && table.config.ignoreCase ? s.toLocaleLowerCase() : s ) : s;
 		},
 		type: "numeric"
 	});
@@ -1304,7 +1306,8 @@
 			return (/^\(?\d+[\u00a3$\u20ac\u00a4\u00a5\u00a2?.]|[\u00a3$\u20ac\u00a4\u00a5\u00a2?.]\d+\)?$/).test((s || '').replace(/[,. ]/g,'')); // £$€¤¥¢
 		},
 		format: function(s, table) {
-			return s ? ts.formatFloat(s.replace(/[^\w,. \-()]/g, ""), table) : s;
+			var n = ts.formatFloat((s || '').replace(/[^\w,. \-()]/g, ""), table);
+			return s && typeof n === 'number' ? n : s ? $.trim( s && table.config.ignoreCase ? s.toLocaleLowerCase() : s ) : s;
 		},
 		type: "numeric"
 	});