problems running headless ANT

We are using RAD 7.0 for EJB developemnt. We are facing problems with the ANT build scripts.

The tasks in the script are as follows;

CVS checkout using projectImport

The script runs perfectly fine if I use all the settings of RAD i.e as follows;

set WAS_60_INSTALLDIR=D:\IBM\SDP70\runtimes\base_v61
set JAVA_DIR=D:\IBM\SDP70\jdk\bin

But we are getting following errors when using Websphere AST 6.1.1 with settings as below during the workspaceBuild and



set WAS_60_INSTALLDIR=D:\WebSphere\AST\runtimes\base_v 61_stub
set AST_DIR=D:\WebSphere\AST\eclipse
set JAVA_DIR=D:\WebSphere\AST\eclipse\jre\bin


[workspaceBuild] WorkspaceBuild (Done)
[workspaceBuild] ERROR: [0]. Type=org.eclipse.wst.common.project.facet.core.val idation.marker Line
=0 Resource=\CFS
[workspaceBuild] ERROR: [0].. Message=Target runtime WebSphere Application Server v6.1 is not define
[workspaceBuild] ERROR: [1]. Type=org.eclipse.jdt.core.problem Line=0 Resource=\CFS
[workspaceBuild] ERROR: [1].. Message=The project was not built since its build path is incomplete.
Cannot find the class file for java.lang.Object. Fix the build path then try building this project
[workspaceBuild] ERROR: [2]. Type=org.eclipse.jdt.core.problem Line=1 Resource=\CFS\ejbModule\com
\ac\cfs\notification\NotificationServiceLocalHome. java
[workspaceBuild] ERROR: [2].. Message=The type java.lang.Object cannot be resolved. It is indirectly
referenced from required .class files
[workspaceBuild] WorkspaceGetErrors: Exception=workspaceGetErrors FAIL-ON-ERROR. errorCount=3 erro
rMessage[1]=Target runtime WebSphere Application Server v6.1 is not defined.
[ant] Exiting D:\Auto Build\AST611\master_build.xml.

Any ideas on the root cause of the errors or any work-arounds are welcome.