WAS 6.1 Express error on iSeries

[mikrom]

I have WAS 6.1 Express installed and running on an iSeries machine.
But when I try to switch from 64-bit JVM to 32-bit JVM with the command

enableJVM -jvm std32 -profile [i]ourProfile[/i]

it doesn't work and I get these errors

java.lang.reflect.InvocationTargetException                                                                                      
          at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)                                                           
          at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:79)                                         
          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)                                 
          at java.lang.reflect.Method.invoke(Method.java:618)                                                                      
          at com.ibm.wsspi.bootstrap.WSLauncher.launchMain(WSLauncher.java:183)                                                    
          at com.ibm.wsspi.bootstrap.WSLauncher.main(WSLauncher.java:90)                                                           
          at com.ibm.wsspi.bootstrap.WSLauncher.run(WSLauncher.java:72)                                                            
          at org.eclipse.core.internal.runtime.PlatformActivator$1.run(PlatformActivator.java:78)                                  
          at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:92)               
          at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:68)                        
          at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:400)
          at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:177)                                          
          at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)                                                           
          at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:79)                                         
          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)                                 
          at java.lang.reflect.Method.invoke(Method.java:618)                                                                      
          at org.eclipse.core.launcher.Main.invokeFramework(Main.java:336)                                                         
          at org.eclipse.core.launcher.Main.basicRun(Main.java:280)                                                                
          at org.eclipse.core.launcher.Main.run(Main.java:977)                                                                     
          at com.ibm.wsspi.bootstrap.WSPreLauncher.launchEclipse(WSPreLauncher.java:329)                                           
          at com.ibm.wsspi.bootstrap.WSPreLauncher.main(WSPreLauncher.java:92)                                                     
  Caused by: java.lang.NoSuchMethodError: com/ibm/as400/access/Product.<init>(Lcom/ibm/as400/access/AS400;Ljava/lang/String;Ljava/l
  ang/String;)V                                                                                                                    
          at com.ibm.ws.os400.tools.EnableJVM.isJVMInstalled(EnableJVM.java:435)                                                   
          at com.ibm.ws.os400.tools.EnableJVM.validateParms(EnableJVM.java:379)                                                    
          at com.ibm.ws.os400.tools.EnableJVM.main(EnableJVM.java:170)                                                             
          ... 21 more

On other iSeries machines the switching between JVMs works fine.

Are the above Errors caused by bad installation of WAS or by bad installation of JVM or what's going on?

Any suggestion appreciated !