Login error in Service Studio

I cannot login at Service Studio.
I get the following error:
There was an error contacting 'SERVER_NAME'
Could not find ServiceCenter at http://SERVER_NAME

But I'm able to login to Service Center through the browser with no problems.
I've checked the General Log, the Error Log and Event Viewer and I have no errors there.
I've restarted all services and still the error happens
Eventually I found the error.
I was using a proxy in IE to access the web and it seems that Service Studio uses this definitions somehow.
After removing the proxy configurations from IE I could login in Service Studio.