Program delayed in ICE-Grid, Help!

Hi, I have writen a Program used ICE Grid . The Program contains an ICE grid with two grid nodes, they are two ICE Server. They running on Redhat Linux AS 4 OS. The ICE version is 3.1.1. But, when remote ICE Clients are firing requests to any of the two ICE Server, the time it takes to connect to server is either immediate or 20 seconds.:(

In the code,I get two places where will delay the program running.
The first is connect to icegrid.The codes as follows:
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Ice.Properties pro = Ice.Util.createProperties();
pro.load(configFile);

ic = Ice.Util.initializeWithProperties(new String[0], pro);
Ice.ObjectAdapter adapter = ic.createObjectAdapter("clientAdapter");
ClientReceiverI object = new ClientReceiverI();
Ice.ObjectPrx base = adapter.add(object, Ice.Util.stringToIdentity("cObject"));
adapter.activate();
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When running to "adapter.activate();", it will delay about 20 seconds.



The second is get ICE object.The codes as follows:
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try{
Ice.ObjectPrx base = ic.stringToProxy("IceGrid/Query");
IceGrid.QueryPrx query = IceGrid.QueryPrxHelper.checkedCast(base);
IDSPrxs = query.findAllObjectsByType("TeleControl");
System.out.println("IDSPrxs.length="+IDSPrxs.length);
}catch(Ice.LocalException e){
e.printStackTrace();
}catch(Exception e){
e.printStackTrace();
}

TeleControlPrxMap.clear();
if(IDSPrxs != null && IDSPrxs.length > 0){
try{
for(int i = 0 ; i < IDSPrxs.length; i++){
proxyVector.addElement(IDSPrxs);

TeleControlPrx proxy = TeleControlPrxHelper.checkedCast(IDSPrxs);
String prxIP = proxy.getProxyIP();
IPVector.addElement(prxIP);
TeleControlPrxMap.put(prxIP, proxy);
}
}catch(Exception e){
e.printStackTrace();
}
}
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When running to "TeleControlPrx proxy = TeleControlPrxHelper.checkedCast(IDSPrxs);" ,will delay about from 20 second to 5 minutes.

I debug the code ,track the runing into "TeleControlPrxHelper.checkedCast",I see it will delay in the code like this:
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__obj.ice_isA("::com::wiscom::IDSConsoleProxy::TeleControl");
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The Class of the instance "__obj" is "ICE.ObjectPrx".

I can't resolve this questions, and I don't know the reason of the delay.

I have troubled with this problem for several weeks, Please Help me ,very thanks!!!