Why is curl slow than browser?

I am using this class to make one GET and another POST request to a website (the first request is to set a cookie). I am testing in a Win XP virtual machine with virtualbox, using wamp from wampserver dot com. The 2 requests takes from 10 to 18 seconds (with curl), but if I make those request directly via the webbrowser in that same virtual machine the website loads in just a few seconds, and it retrieves all the images, css, etc.

What could be causing curl to work so slow? is there a way to fix it?

I ran into this issue with a local web server. I was able to fix by adding

::1 localhost

to /etc/hosts/ file.

This is the ipv6 notation for