ERROR-Cannot expand .ear file

[Veni Velkoor]

Hello,
We are running WAS v.4.0.1 on a Win2K server. Using the AAT tool, I successfully created a .war file. We only have servlets and JSPs and NO EJBs. So Now I tried to Install the application consisting of this single war file using the "INstall Enterprise Application Wizard" on the Admin console. I get the following error on clicking finish at the last step----

Exception:
Cannot expand the ear file under E:\WebSphere\AppServer\installedApps\CLCS_GUI.ear
com.ibm.ejs.sm.exception.OpException: Cannot expand the ear file under E:\WebSphere\AppServer\installedApps\CLCS_GUI.ear
--------
com.ibm.ejs.sm.client.command.ExecutionException: Error during install application at com.ibm.ejs.sm.client.command.InstallEnterpriseAppCommand.execute(InstallEnterpriseAppCommand.java:84) at com.ibm.ejs.sm.client.command.CommandManager$ExecutionThread.run(CommandManager.java:264) at com.ibm.ejs.sm.client.command.ThreadPool$PooledThread.run(ThreadPool.java:89)
Any ideas???
Thanks,
Veni