The simplest solution is to go directly to

http://www.GIDEONonline.net/authx.php?user=metalib&browser_ok=1
[download]

instead of

http://www.GIDEONonline.net/loginx.php?user=metalib
[download]

The Javascript on the page you retrieved is simply redirecting you to this location. And LWP::UserAgent does not understand this, as it has no embedded Javascript engine :)

Generally, if you want to process pages containing JavaScript with LWP::UserAgent, you must carefully read all javascript on the pages you retrieve and decide what workaround to choose in every certain case.

In the worst cases Javascript module is the only solution.