Hey, I've been running zimbra 5.0.9 in Ubuntu 8. When user try to login in zimbra, error occured " A network service error has occurred (zclient/io)".
This problem will be solved if I execute the command zmcontrol stop and then zmcontrol start.
But, this is not solve the problem because in the specific time, the error will be happened again.
I have try to check the error by execute " tail -f /opt/zimbra/log/mailbox.log"

and the result is :
at org.mortbay.jetty.HttpConnection.handle(HttpConnec tion.java:381)
at org.mortbay.io.nio.SelectChannelEndPoint.run(Selec tChannelEndPoint.java:396)
at org.mortbay.thread.BoundedThreadPool$PoolThread.ru n(BoundedThreadPool.java:442)
Caused by: com.zimbra.common.soap.SoapParseException: cannot determine soap protocol in reply: <html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"/><title>Error 503 SERVICE_UNAVAILABLE</title></head><body><h2>HTTP ERROR: 503</h2><pre>SERVICE_UNAVAILABLE</pre><p>RequestURI=/service/soap</p><p><i><small><a href="http://jetty.mortbay.org">Powered by jetty://</a></small></i></p></body></html>
at com.zimbra.common.soap.SoapTransport.extractBodyEl ement(SoapTransport.java:228)
at com.zimbra.common.soap.SoapTransport.parseSoapResp onse(SoapTransport.java:221)
at com.zimbra.common.soap.SoapHttpTransport.invoke(So apHttpTransport.java:251)
at com.zimbra.common.soap.SoapTransport.invoke(SoapTr ansport.java:297)
at com.zimbra.cs.zclient.ZMailbox.invoke(ZMailbox.jav a:526)
... 49 more

Is there any problem with the soap protocol?
Any help much appreciated.