Index: user_import.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/user_import/user_import.module,v
retrieving revision 1.17.2.4
diff -u -p -r1.17.2.4 user_import.module
--- user_import.module	23 Jul 2007 22:49:45 -0000	1.17.2.4
+++ user_import.module	29 Nov 2007 20:10:25 -0000
@@ -1171,7 +1171,7 @@ function _user_import_sanitise_username(
     if ($sanitised == 0) {
   
         // username cannot contain an illegal character
-        $username = preg_replace('/[^a-zA-Z0-9@ ]/', ' ', $username);
+        $username = preg_replace('/[^a-zA-Z0-9@ ._-]/', ' ', $username);
         // username cannot contain multiple spaces in a row
         $username = preg_replace('/[ ]+/', ' ', $username);