Index: includes/install.core.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/install.core.inc,v
retrieving revision 1.46
diff -u -p -r1.46 install.core.inc
--- includes/install.core.inc	4 Dec 2010 01:54:37 -0000	1.46
+++ includes/install.core.inc	28 Dec 2010 16:15:03 -0000
@@ -1374,9 +1374,15 @@ function install_profile_modules(&$insta
  */
 function install_import_locales(&$install_state) {
   include_once DRUPAL_ROOT . '/includes/locale.inc';
-  $install_locale = $install_state['parameters']['locale'];
+  
+  // The locale (file name) might be drupal-7.2.cs.po instead of cs.po.
+  // Normalize the locale for addition to Drupal. locale_batch_by_language()
+  // will find the file with this language suffix nevertheless.
+  $install_locale = preg_replace('!^(.+\.)?([^\.]+)$!', '\2', $install_state['parameters']['locale']);
+  
   // Enable installation language as default site language.
   locale_add_language($install_locale, NULL, NULL, NULL, '', NULL, 1, TRUE);
+  
   // Collect files to import for this language.
   $batch = locale_batch_by_language($install_locale, NULL);
   if (!empty($batch)) {
Index: INSTALL.txt
===================================================================
RCS file: /cvs/drupal/drupal/INSTALL.txt,v
retrieving revision 1.85
diff -u -p -r1.85 INSTALL.txt
--- INSTALL.txt	7 Nov 2010 21:54:44 -0000	1.85
+++ INSTALL.txt	28 Dec 2010 16:15:03 -0000
@@ -91,8 +91,7 @@ INSTALLATION
    - Download a translation file for the correct Drupal version and language
      from the translation server: http://localize.drupal.org/download
 
-   - Rename the downloaded file to your language's ISO code (e.g., de.po or
-     fr.po) and place it into your installation profile's translations
+   - Place the file into your installation profile's translations
      directory. For instance, if you are using the Standard install profile,
      move the .po file into the directory: