diff -Naur mw118a/includes/specials/SpecialBlock.php mw118/includes/specials/SpecialBlock.php
--- mw118a/includes/specials/SpecialBlock.php	2011-10-25 14:33:18.000000000 -0700
+++ mw118/includes/specials/SpecialBlock.php	2012-08-27 12:27:51.764350835 -0700
@@ -251,7 +251,14 @@
 			if( isset( $fields['DisableUTEdit'] ) ){
 				$fields['DisableUTEdit']['default'] = $block->prevents( 'editownusertalk' );
 			}
-			$fields['Reason']['default'] = $block->mReason;
+
+			// If the username was hidden (ipb_deleted == 1), don't show the reason
+			// unless this user also has rights to hideuser: Bug 35839
+			if ( !$block->mHideName || $wgUser->isAllowed( 'hideuser' ) ) {
+				$fields['Reason']['default'] = $block->mReason;
+			} else {
+				$fields['Reason']['default'] = '';
+			}
 
 			if( $wgRequest->wasPosted() ){
 				# Ok, so we got a POST submission asking us to reblock a user.  So show the