Error using RAM 7.5 web UI

I have installed RAM 7.5 in a RHEL 5.5 box, with DB2 9.7 and WAS 7.0.0.13, and RAM and RTC in the same WAS profile (RTC installed when installing RAM).
I can login into RAM Web UI as admin user, but when trying to access Configuration page I get this error:

0000001a servlet E com.ibm.ws.webcontainer.servlet.ServletWrapper service SRVE0068E: Uncaught exception created in one of the service methods of the servlet Faces Servlet in application RAM1WebApplication. Exception created : javax.servlet.ServletException: java.lang.IllegalArgumentException: Cannot convert ram.repositoryprocess
dbUser=com.ibm.ram.repository.sdo.impl.UserImpl@2efb2efb (id: 2, userid: ram.repositoryprocess, name: %nls.repository_process_user_name Repository Process, email: null, phone: null, emailFormatId: 0, subscriptionFrequencyId: 0, userStatusId: 1, loginid: ~ram.repositoryprocess) of type class com.ibm.ram.repository.security.RegisteredUser to class java.lang.Boolean
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:277)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1663)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1597)
at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:131)
at com.ibm.ram.repository.web.security.RAMServletFilter.doFilter(RAMServletFilter.java:442)
at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:188)
at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:116)
at com.ibm.ram.repository.web.filters.GZipFilter.doFilter(GZipFilter.java:42)
at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:188)
at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:116)
at com.ibm.ws.webcontainer.filter.WebAppFilterChain._doFilter(WebAppFilterChain.java:77)
at com.ibm.ws.webcontainer.filter.WebAppFilterManager.doFilter(WebAppFilterManager.java:908)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:934)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:502)
at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:179)
at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:3826)
at com.ibm.ws.webcontainer.webapp.WebGroup.handleRequest(WebGroup.java:276)
at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:931)
at com.ibm.ws.webcontainer.WSWebContainer.handleRequest(WSWebContainer.java:1583)
at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:186)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:445)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewRequest(HttpInboundLink.java:504)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.processRequest(HttpInboundLink.java:301)
at com.ibm.ws.http.channel.inbound.impl.HttpICLReadCallback.complete(HttpICLReadCallback.java:83)
at com.ibm.ws.tcp.channel.impl.AioReadCompletionListener.futureCompleted(AioReadCompletionListener.java:165)
at com.ibm.io.async.AbstractAsyncFuture.invokeCallback(AbstractAsyncFuture.java:217)
at com.ibm.io.async.AsyncChannelFuture.fireCompletionActions(AsyncChannelFuture.java:161)
at com.ibm.io.async.AsyncFuture.completed(AsyncFuture.java:138)
at com.ibm.io.async.ResultHandler.complete(ResultHandler.java:204)
at com.ibm.io.async.ResultHandler.runEventProcessingLoop(ResultHandler.java:775)
at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:905)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1563)
Caused by: javax.el.ELException: java.lang.IllegalArgumentException: Cannot convert ram.repositoryprocess
dbUser=com.ibm.ram.repository.sdo.impl.UserImpl@2efb2efb (id: 2, userid: ram.repositoryprocess, name: %nls.repository_process_user_name Repository Process, email: null, phone: null, emailFormatId: 0, subscriptionFrequencyId: 0, userStatusId: 1, loginid: ~ram.repositoryprocess) of type class com.ibm.ram.repository.security.RegisteredUser to class java.lang.Boolean
at javax.faces.component.ValueExpressionValueBindingAdapter.getValue(ValueExpressionValueBindingAdapter.java:92)
at javax.faces.component.UIComponentBase.isRendered(UIComponentBase.java:384)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:930)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:942)
at com.sun.faces.application.ViewHandlerImpl.doRenderView(ViewHandlerImpl.java:292)
at com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:223)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:114)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:266)
... 31 more
Caused by: java.lang.IllegalArgumentException: Cannot convert ram.repositoryprocess
dbUser=com.ibm.ram.repository.sdo.impl.UserImpl@2efb2efb (id: 2, userid: ram.repositoryprocess, name: %nls.repository_process_user_name Repository Process, email: null, phone: null, emailFormatId: 0, subscriptionFrequencyId: 0, userStatusId: 1, loginid: ~ram.repositoryprocess) of type class com.ibm.ram.repository.security.RegisteredUser to class java.lang.Boolean
at org.apache.el.lang.ELSupport.coerceToBoolean(ELSupport.java:167)
at org.apache.el.parser.AstNot.getValue(AstNot.java:27)
at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:263)
at com.sun.faces.application.ValueBindingValueExpressionAdapter.getValue(ValueBindingValueExpressionAdapter.java:113)
at javax.faces.component.ValueExpressionValueBindingAdapter.getValue(ValueExpressionValueBindingAdapter.java:89)
... 40 more

I get same error when accesing other pages, for example trying to submit an asset. Any idea?
Regards,
-unai