Index: wp-admin/import/wordpress.php
===================================================================
--- wp-admin/import/wordpress.php	(revision 14387)
+++ wp-admin/import/wordpress.php	(working copy)
@@ -248,7 +248,7 @@
 	function users_form($n, $author) {
 
 		if ( $this->allow_create_users() ) {
-			printf('<label>'.__('Create user %1$s or map to existing'), ' <input type="text" value="'. esc_attr($author) .'" name="'.'user_create['.intval($n).']'.'" maxlength="30" /></label> <br />');
+			printf('<label>'.__('Create user %1$s or map to existing'), ' <input type="text" value="'. sanitize_user($author, true) .'" name="'.'user_create['.intval($n).']'.'" maxlength="30" /></label> <br />');
 		}
 		else {
 			echo __('Map to existing').'<br />';