I try to follow the instructions from here to install a Visual editor pulgin for Eclipse: http://wiki.eclipse.org/VE/Update

Both online and offline installations fails with the following mistake: Cannot complete request. Generating details.

Here is the complete log:

Cannot complete the install because of a conflicting dependency.
  Software being installed: Java EMF Model 1.4.0.v20090826-1446-7H-FPbAcggQleH8hJifHfUd (org.eclipse.jem.feature.group 1.4.0.v20090826-1446-7H-FPbAcggQleH8hJifHfUd)
  Software currently installed: Eclipse IDE for Java EE Developers 1.2.2.20100217-2310 (epp.package.jee 1.2.2.20100217-2310)
  Only one of the following can be installed at once: 
    Java EMF Model BeanInfo (Introspection) Support 2.0.300.v200905030615 (org.eclipse.jem.beaninfo 2.0.300.v200905030615)
    Java EMF Model BeanInfo (Introspection) Support 2.0.300.R3_1_maintenance (org.eclipse.jem.beaninfo 2.0.300.R3_1_maintenance)
  Cannot satisfy dependency:
    From: Eclipse IDE for Java EE Developers 1.2.2.20100217-2310 (epp.package.jee 1.2.2.20100217-2310)
    To: org.eclipse.epp.package.jee.feature.feature.group [1.2.2.20100217-2310]
  Cannot satisfy dependency:
    From: Java EE IDE Feature 1.2.2.20100217-2310 (org.eclipse.epp.package.jee.feature.feature.group 1.2.2.20100217-2310)
    To: org.eclipse.jst.web_ui.feature.feature.group 0.0.0
  Cannot satisfy dependency:
    From: Java EMF Model 1.4.0.v20090826-1446-7H-FPbAcggQleH8hJifHfUd (org.eclipse.jem.feature.group 1.4.0.v20090826-1446-7H-FPbAcggQleH8hJifHfUd)
    To: org.eclipse.jem.beaninfo [2.0.300.R3_1_maintenance]
  Cannot satisfy dependency:
    From: JST Web Core 3.1.1.v200908121609-7S7CFyvFIhIehVidwyfk0m (org.eclipse.jst.web_core.feature.feature.group 3.1.1.v200908121609-7S7CFyvFIhIehVidwyfk0m)
    To: org.eclipse.jem.beaninfo [2.0.300.v200905030615]
  Cannot satisfy dependency:
    From: JST Web Core 3.1.1.v200908121609-7S7CG-dFIhIeq7kV6qxaLD (org.eclipse.jst.web_core.feature.feature.group 3.1.1.v200908121609-7S7CG-dFIhIeq7kV6qxaLD)
    To: org.eclipse.jem.beaninfo [2.0.300.v200905030615]
  Cannot satisfy dependency:
    From: JST Web UI 3.1.1.v200908121609-7E77FBfDlwYa_9sdy2q77doi14gl (org.eclipse.jst.web_ui.feature.feature.group 3.1.1.v200908121609-7E77FBfDlwYa_9sdy2q77doi14gl)
    To: org.eclipse.jst.web_core.feature.feature.group [3.1.1.v200908121609-7S7CFyvFIhIehVidwyfk0m]
  Cannot satisfy dependency:
    From: JST Web UI 3.1.1.v200908121609-7E77FBiDlwYcICNdz-5z-9PGqZCy (org.eclipse.jst.web_ui.feature.feature.group 3.1.1.v200908121609-7E77FBiDlwYcICNdz-5z-9PGqZCy)
    To: org.eclipse.jst.web_core.feature.feature.group [3.1.1.v200908121609-7S7CG-dFIhIeq7kV6qxaLD]

Has anybody encountered something like this? Appreciate your ideas!