Index: commands/pm/pm.drush.inc
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/drush/commands/pm/pm.drush.inc,v
retrieving revision 1.23
diff -u -p -u -p -r1.23 pm.drush.inc
--- commands/pm/pm.drush.inc	19 Apr 2009 19:51:55 -0000	1.23
+++ commands/pm/pm.drush.inc	21 Apr 2009 21:07:53 -0000
@@ -478,7 +478,7 @@ function pm_dl_destination($type) {
 
   // If a URI is provided and we bootstrapped successfully then we install to
   // that specific site, otherwise we install to sites/all/modules
-  if ($site_root) {
+  if ($site_root && $site_root !== 'sites/default') {
     $sitepath = $drupal_root .'/'. $site_root .'/';
   }
   else if ($drupal_root) {