diff --git a/bureau/admin/bro_tgzdown.php b/bureau/admin/bro_tgzdown.php
index 5a0ce9fe..7f1a4ee8 100644
--- a/bureau/admin/bro_tgzdown.php
+++ b/bureau/admin/bro_tgzdown.php
@@ -36,6 +36,9 @@ getFields($fields);
 
 
 $p=$bro->GetPrefs();
+// need to release the giant lock, otherwise those downloads will hang
+// AlternC for all users!
+alternc_shutdown();
 switch ($p["downfmt"]) {
 	case 0:
 		$bro->DownloadTGZ($dir);
diff --git a/bureau/class/m_bro.php b/bureau/class/m_bro.php
index 2a6cd35e..0a545479 100644
--- a/bureau/class/m_bro.php
+++ b/bureau/class/m_bro.php
@@ -1041,6 +1041,9 @@ class m_bro {
     }
     $timestamp=date("H:i:s");
 
+    // relacher le lock global sinon ce download va geler alternc pour
+    // tout le monde
+    alternc_shutdown();
     if(exec("/bin/tar cvf -  ".getuserpath()."/ | gzip -9c > ".$dir."/".$mem->user['login']."_html_".$timestamp.".tar.gz")){
       $err->log("bro","export_data_succes");
     }else{