After installing last Systempatches Proxy Server is failing

Hi,
i have installed the last Systempatches for opensuse. After that no Internetconnection is possible anymore.
The login to the proxy Server, i have configured is failing with wrong User/PW.
The proxy Server test in yast is also failing:

  • Rebuilt URL to: http://www.novell.com/

  • About to connect() to proxy 10.252.76.110 port 8080 (#0)

  • Trying 10.252.76.110…

  • Adding handle: conn: 0x18c5090

  • Adding handle: send: 0

  • Adding handle: recv: 0

  • Curl_addHandleToPipeline: length: 1

    • Conn 0 (0x18c5090) send_pipe: 1, recv_pipe: 0
      % Total % Received % Xferd Average Speed Time Time Time Current
      Dload Upload Total Spent Left Speed

    0 0 0 0 0 0 0 0 --:–:-- --:–:-- --:–:-- 0* Connected to 10.252.76.110 (10.252.76.110) port 8080 (#0)

  • Proxy auth using Basic with user ‘christian.strakhof’
    > GET http://www.novell.com/ HTTP/1.1
    > Proxy-Authorization: Basic Y2hyaXN0aWFuLnN0cmFraG9mOmZlbGl4
    > User-Agent: curl/7.32.0
    > Host: www.novell.com
    > Accept: /
    > Proxy-Connection: Keep-Alive
    >
    < HTTP/1.1 301 Moved Permanently
    < Date: Thu, 26 Jun 2014 06:39:25 GMT

  • Server Apache is not blacklisted
    < Server: Apache
    < Location: http://www.novell.com/home/
    < Content-Length: 319
    < Age: 364
    < X-Mag: 7CFDEB6C02633A18;911bf594;50314631;usrLkup->0;usrBase->0;getPRBefFind->0;getPRBefFind->0;PRAfterFind->0;www_root;publicURL->0;FP4->0;
    < Via: 1.1 www.novell.com (Access Gateway-ag-7CFDEB6C02633A18-50314631)
    < Content-Type: text/html; charset=iso-8859-1
    < Proxy-Connection: Keep-Alive
    < Connection: Keep-Alive
    < Set-Cookie: lb_novell=NNODEBIJ; Domain=.novell.com; Path=/
    <
    { [data not shown]

100 319 100 319 0 0 554 0 --:–:-- --:–:-- --:–:-- 554
100 319 100 319 0 0 554 0 --:–:-- --:–:-- --:–:-- 553

  • Connection #0 to host 10.252.76.110 left intact

I have now installed Opensuse 13.1 completly new from cd. Everthing worked fine until i upgraded the system with the last actual software.
Has anybody an idea?
Christian

Some additional Infos.
using wget with --prox-user --proxy-password, connection is working fine.
Then also the Browser connection is working for a while.
After some minutes cannection in browser is failing again.
is there any time limit?

That would be a function of the proxy server.