My server had a problem connecting to WPMU


I am trying to setup a test WP network on a new server and I began by installing the WPMUDEV Dashboard plugin.

1) I network activated it

2) then I go to the WPMU dasboard page where I see the 'login to wpmu dev' form

3) then I submit the form with my credentials (working on my production server)

4) then, after about 10 seconds hangout, I get the error:

"Your server had a problem connecting to WPMU DEV: "I/O operation timed out" Please try again.
If this problem continues, please contact your host and ask:
"Is php on my server properly configured to be able to contact with a GET HTTP request via fsockopen or CURL?"

But CURL is installed on the server and the other GET HTTP features work fine (as the auto update notifications, or the display of wordpress news rss feed on the dashboard).

I add that the 'WPMU DEV news' rss feeds window is also not working on the dashboard, returning:

"Erreur RSS : WP HTTP Error: Operation timed out after 10454 milliseconds with 3655 out of -1 bytes received"

So it seams your server is refusing connections from mine.

Do I have to parameter somewhere the IP or domain name of my new test server ?