--- a/bin/update	Fri Mar 16 15:03:31 2012 +0200
+++ b/bin/update	Fri Mar 16 15:17:12 2012 +0200
@@ -269,7 +269,8 @@
 ## bin wrappers
 function update_serial {
     local serial=$1; shift
-    local old=$(cat $serial)
+    
+    local old=$(test -e $serial && cat $serial || echo '')
 
     log_info "Updating serial: $serial"