http-client not redirecting?

(use http-client)

;; A simple GET request:
(with-input-from-request "http://start.csail.mit.edu/" #f read-string)
 => "<head>\n<meta http-equiv=\"refresh\" content=\"0; url=index.php\">\n</head>\n<body>\n</body>\n"

;; but I expected the above to redirect to
;; http://start.csail.mit.edu/index.php, and get the exact same result as if I had ran:

(with-input-from-request "http://start.csail.mit.edu/index.php" #f read-string)
 => "<!DOCTYPE html>\n<!--[if IE 8]>    <html class=\"no-js lt-ie9\" lang=\"en\"> <![endif]-->\n<!--[if gt IE 8]><!--> <html class=\"no-js\" lang=\"en\"> <!--<![endif]-->\n  <html xmlns=\"http://www.w3.org/1999/xhtml\" lang=\"en\" xml:lang=\"en\">\n    <head>\n      <meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\"/>\n      <title>The START Natural Language Question Answering System</title>\n      <meta name=\"description\" content=\"Come check out our demos and ask our systems questions in English! The MIT InfoLab Group develops intelligent interactive software systems that help people access information and solve problems on human terms.\"/>\n      <meta name=\"keywords\" content=\"natural language\"/>\n      <meta name=\"keywords\" content=\"natural language processing\"/>\n      <meta name=\"keywords\" content=\"question answering system\"/>\n      <meta name=\"keywords\" content=\"information retrieval\"/>\n      <meta name=\"keywords\" content=\"information access\"/>\n      <meta name=\"keywords\" content=\"START information access system\"/>\n      <meta name=\"keywords\" content=\"ternary expression\"/>\n      <meta name=\"keywords\" content=\"ternary expressions\"/>\n      <meta name=\"keywords\" content=\"multimedia\"/>\n      <meta name=\"keywords\" content=\"map\"/>\n      <meta name=\"keywords\" content=\"geography\"/>\n      <meta name=\"keywords\" content=\"Artificial Intelligence\"/>\n      <meta name=\"keywords\" content=\"AI Laboratory\"/>\n      <meta name=\"keywords\" content=\"Artificial Intelligence Laboratory\"/>\n      <meta name=\"keywords\" content=\"CSAIL\"/>\n      <meta name=\"keywords\" content=\"Computer Science and Artificial Intelligence Laboratory\"/>\n\n      <link rel=\"search\" type=\"application/opensearchdescription+xml\" title=“START\" href=\"opensearch.xml\">\n<link rel=\"shortcut icon\" type=\"image/x-icon\" href=\"images/favicon.ico\" />\n\n<link rel=\"stylesheet\" href=\"./bootstrap/css/bootstrap.css\" /> \n<link rel=\"stylesheet\" href=\"./bootstrap...