Blank screen when trying to enter manager

Hi,

I’m new at Modx, so my question might be stupid, so sorry for that

When I try to navigate to my /manager (after a successfull installation), I get a login screen. When I fill in my credentials and try to login I just get a blank screen (after 30 seconds).
Does anyone have an idea what can be the source of the problem?

Some specs:
OS: windows server 2008 x64
WAMP v2.1
Modx 2.0.8-pl (traditional installation)
Contents of the error-log:
[2011-03-18 12:21:52] (ERROR @ C:\wamp\www\core\model\modx\xmlrss\rssfetch.class.php : 242) User warning: MagpieRSS: Failed to fetch http://feeds.feedburner.com/modx-announce (HTTP Error: connection failed (1006)
[2011-03-18 12:21:52] (ERROR @ C:\wamp\www\manager\controllers\default\welcome.php : 64) PHP warning: array_keys() expects parameter 1 to be array, null given
[2011-03-18 12:21:52] (ERROR @ C:\wamp\www\manager\controllers\default\welcome.php : 64) PHP warning: Invalid argument supplied for foreach()

Thanks

I am getting exactly the same problem:


I have tried in Firefox4, Chrome/Iron and IE9.
Some of the MODx buttons work, and I could Clear cache and Remove locks.
The logout does not work.

Revo 2.1.2 Traditional
Apache

anyone ?
this is kind of a random problem in the sense that I created a new MODx install on a different domain and I can access the Manager fine.