I change the hostname by typing hostname MYNEWEHOSTNAME

restarted zimbra all works fine but now I needed to reboot the system and mailbox did not start (or started and stopped again)

this is what the mailbox.log say's (from where the error occurs)
Code:
2009-01-12 12:03:57,918 INFO  [main] [] system - Setting mysql connector property: maxActive=100
2009-01-12 12:03:58,069 FATAL [main] [] system - Config initialization failed
com.zimbra.common.service.ServiceException: system failure: getting all config entries
ExceptionId:main:1231758238068:46d4502cfd85f9f6
Code:service.FAILURE
        at com.zimbra.common.service.ServiceException.FAILURE(ServiceException.java:253)
        at com.zimbra.cs.db.DbConfig.getAll(DbConfig.java:166)
        at com.zimbra.cs.util.Config.init(Config.java:66)
        at com.zimbra.cs.util.Config.initConfig(Config.java:91)
        at com.zimbra.cs.util.Config.getString(Config.java:103)
        at com.zimbra.cs.db.Versions.checkDBVersion(Versions.java:77)
        at com.zimbra.cs.db.Versions.checkVersions(Versions.java:73)
        at com.zimbra.cs.util.Zimbra.startup(Zimbra.java:156)
        at com.zimbra.cs.util.Zimbra.startup(Zimbra.java:129)
        at com.zimbra.soap.SoapServlet.init(SoapServlet.java:114)
        at javax.servlet.GenericServlet.init(GenericServlet.java:241)
        at org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:433)
        at org.mortbay.jetty.servlet.ServletHolder.doStart(ServletHolder.java:256)
        at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
        at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:612)
        at org.mortbay.jetty.servlet.Context.startContext(Context.java:139)
        at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1222)
        at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:501)
        at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:449)
        at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
        at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:147)
        at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:161)
        at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
        at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:147)
        at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
        at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:117)
        at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
        at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:117)
        at org.mortbay.jetty.Server.doStart(Server.java:217)
        at org.mortbay.setuid.SetUIDServer.doStart(SetUIDServer.java:100)
        at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
        at org.mortbay.xml.XmlConfiguration.main(XmlConfiguration.java:979)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at org.mortbay.start.Main.invokeMain(Main.java:183)
        at org.mortbay.start.Main.start(Main.java:497)
        at org.mortbay.start.Main.main(Main.java:115)
Caused by: java.sql.SQLException: Incorrect information in file: './zimbra/config.frm'

Query being executed when exception was thrown:

SELECT * FROM config
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:946)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2870)
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1573)
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1665)
        at com.mysql.jdbc.Connection.execSQL(Connection.java:3124)
        at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1149)
        at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1262)
        at org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:205)
        at com.zimbra.cs.db.DbConfig.getAll(DbConfig.java:160)
        ... 37 more
this part is also weard:
Code:
Caused by: java.sql.SQLException: Incorrect information in file: './zimbra/config.frm'
this file does not exist, there is a file called config.7558 but user zimbra has no rights to read that file.

I tryed copying that file to config.frm and zet chmod to 777 but that did not help.

I have no idea what the error means and where to look at. the system worked fine for some weeks.

Help would be very much appreciated.
especially because this is a production/live server and mail is now not working.

Dimitri