diff -r 4629ad98ee88 -r 9cdfe82c56cd includes/clientside/jsres.php
--- a/includes/clientside/jsres.php	Sat Jan 03 17:54:26 2009 -0500
+++ b/includes/clientside/jsres.php	Sat Jan 03 18:11:18 2009 -0500
@@ -270,7 +270,8 @@
 header("Last-Modified: $date");
 header("ETag: \"$etag\"");
 header("Expires: $expires");
-header("Content-Length: " . strlen($everything));
+if ( !$do_gzip )
+  header("Content-Length: " . strlen($everything));
 
 $local_end = microtime_float();
 $local_gentime = $local_end - $local_start;