Troubleshoot Widget

Can't for the life of me figure out why the checkbox won't be saved when
you check it and click Save

temp-widget.php

@@ -0,0 +1,80 @@
+<?php
+
+// Props @nickhamze 
+
+function sh_sb_widget_register_widgets() {
+    register_widget( 'sh_sb_widget' );
+}
+
+class sh_sb_widget extends WP_Widget {
+
+    function sh_sb_widget() {
+        $widget_ops = array( 
+			'classname' => 'sh_sb_widget_class', 
+			'description' => 'Display your Social Bartender links.' 
+			); 
+        $this->WP_Widget( 'sh_sb_widget', 'Social Bartender', $widget_ops );
+    }
+
+    function form($instance) {
+        $defaults = array( 'title' => '', 'disable_styles' => false ); 
+        $instance = wp_parse_args( (array) $instance, $defaults );
+        $title = $instance['title'];
+
+        ?>
+        <p><strong><?php _e( 'Set up Social Bartender', 'shaken' ); ?> <a href="/wp-admin/options-general.php?page=sh_sb_settings_page"><?php _e( 'here.', 'shaken' ); ?></a></strong></p>
+
+        <p>
+        	<?php _e( 'Title (optional):', 'shaken' ); ?>
+        	<input class="widefat" name="<?php echo $this->get_field_name( 'title' ); ?>"  type="text" value="<?php echo esc_attr( $title ); ?>" />
+        </p>
+
+        <p>
+			<input class="checkbox" type="checkbox" <?php checked($instance['disable_styles'], true) ?> id="<?php echo $this->get_field_id('disable_styles'); ?>" name="<?php echo $this->get_field_name('disable_styles'); ?>" />
+			<label for="<?php echo $this->get_field_id( 'disable_styles' ); ?>">Disable default styles</label>
+		</p>
+        <?php
+    }
+
+    function update($new_instance, $old_instance) {
+        $instance = $old_instance;
+        $instance['title'] = strip_tags( $new_instance['title'] );
+ 		$instance['disable_styles'] = $new_instance['disable_styles'];
+
+        return $new_instance;
+    }
+
+    function widget($args, $instance) {
+        extract($args);
+
+        echo $before_widget;
+
+	        $title = apply_filters( 'widget_title', $instance['title'] );
+	 		$disable_styles = $instance['disable_styles'];
+
+	        if ( !empty( $title ) ) { 
+	        	echo $before_title . $title . $after_title; 
+	        };
+
+	        if( !$disable_styles ) { ?>
+
+		        <style>
+			        .sh-sb-link {
+						padding: 0 5px;
+					}
+		        </style>
+
+	        <?php }
+
+	        social_bartender();
+
+        echo $after_widget;
+    }
+}
+
+function sh_sb_widget_styles(){
+	wp_enqueue_style( 'sh-sb-widget', SH_SB_DIR.'css/widget.css' );
+}
+
+add_action( 'widgets_init', 'sh_sb_widget_register_widgets' );
+?>