OS: SLES 10 SP3

I got the following message when I try to log on via https://edif.pknds/admin url

Your session has been closed. Please log in.

and as per the /var/log/ifolder3/adminweb.log

2010-02-04 03:55:01,097 [-1235084384] INFO Login - [192.168.0.254] Client Information: admin, 192.168.0.254, Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.2) Gecko/20090730 SUSE/3.5.2-3.4.8 Firefox/3.5.2
2010-02-04 03:55:01,323 [-1235084384] INFO Login - [192.168.0.254] Login Failed
System.InvalidOperationException: Not supported Content-Type in the response: 'text/html; charset=utf-8'
at System.Web.Services.Protocols.WebServiceHelper.Inv alidOperation (System.String message, System.Net.WebResponse response, System.Text.Encoding enc) [0x00000]
at System.Web.Services.Protocols.SoapHttpClientProtoc ol.ReceiveResponse (System.Net.WebResponse response, System.Web.Services.Protocols.SoapClientMessage message, System.Web.Services.Protocols.SoapExtension[] extensions) [0x00000]
at System.Web.Services.Protocols.SoapHttpClientProtoc ol.Invoke (System.String method_name, System.Object[] parameters) [0x00000]
at iFolderAdmin.GetAuthenticatedUser () [0x00000]
at (wrapper remoting-invoke-with-check) iFolderAdmin:GetAuthenticatedUser ()
at Novell.iFolderWeb.Admin.Login.DoLogin (System.String username, System.String password, Boolean check) [0x00000]
2010-02-04 03:55:01,323 [-1235084384] ERROR Global - [192.168.0.254] Application Error
System.InvalidOperationException: Not supported Content-Type in the response: 'text/html; charset=utf-8'
at System.Web.Services.Protocols.WebServiceHelper.Inv alidOperation (System.String message, System.Net.WebResponse response, System.Text.Encoding enc) [0x00000]
at System.Web.Services.Protocols.SoapHttpClientProtoc ol.ReceiveResponse (System.Net.WebResponse response, System.Web.Services.Protocols.SoapClientMessage message, System.Web.Services.Protocols.SoapExtension[] extensions) [0x00000]
at System.Web.Services.Protocols.SoapHttpClientProtoc ol.Invoke (System.String method_name, System.Object[] parameters) [0x00000]
at iFolderAdmin.GetAuthenticatedUser () [0x00000]
at (wrapper remoting-invoke-with-check) iFolderAdmin:GetAuthenticatedUser ()
at Novell.iFolderWeb.Admin.Login.DoLogin (System.String username, System.String password, Boolean check) [0x00000]

please help