I have a problem with zenworks agent,

I changed my "primario server" Ip address by yast from 192.168.0.100 to 198.168.0.110,

I logged in zenworks panel (on https:\\198.168.0.110) on Device-> server I select primary server and refresh it .. and it works! On summary i see:
General Minimize
Alias: linux-znc
Host Name: linux-znc
IP Address: 198.168.0.110
Last Full Refresh: 10:12 AM
Last Contact: 10:12 AM
ZENworks Configuration Management Version: 10.3.1.0
ZENworks Asset Management Version: 10.3.1.60834
ZENworks Agent Version: 10.3.1.34138

But if I try to refresh workstation not works :(
If in workstatio i open Agent propriety i see:
Server ZENworks
Management Zone: ZENzone <-- is OK!
DNS server: 198.168.0.100 <-- old value :(
Address server: 198.168.0.100 <-- old value :(
And in logs:

[DEBUG] [10/08/2010 10:11:03.218] [1336] [ZenworksWindowsService] [29] [] [QuickTasks] [] [Exception calling QuickTaskService.getQuickTasks
Type: System.Net.WebException
Message: Unable to connect to the remote server
Status: ConnectFailure
Response: <null>
Stack Trace:
at System.Net.HttpWebRequest.GetRequestStream()
at System.Web.Services.Protocols.SoapHttpClientProtoc ol.Invoke(String methodName, Object() parameters)
at Novell.Zenworks.QuickTaskManager.QuickTasksService .getQuickTasks(GetQuickTasksRequest GetQuickTasksRequest)
at Novell.Zenworks.QuickTaskManager.QuickTaskWebServi ce.GetQuickTasks(Session session, String identity, String newSecurityTag)

Type: System.Net.Sockets.SocketException
Message: Impossibile stabilire la connessione. Risposta non corretta della parte connessa dopo l'intervallo di tempo oppure mancata risposta dall'host collegato 192.106.230.193:443
Stack Trace:
at System.Net.HttpWebRequest.GetRequestStream()
at System.Web.Services.Protocols.SoapHttpClientProtoc ol.Invoke(String methodName, Object() parameters)
at Novell.Zenworks.QuickTaskManager.QuickTasksService .getQuickTasks(GetQuickTasksRequest GetQuickTasksRequest)
at Novell.Zenworks.QuickTaskManager.QuickTaskWebServi ce.GetQuickTasks(Session session, String identity, String newSecurityTag)

] [] []
What can i do for refresh all agent at new IP server's value?