I don't know if this helps but just in case, these are the details:
Cannot complete the install because of a conflicting dependency.
Software being installed: Android DDMS 16.0.1.v201112150204-238534 (com.android.ide.eclipse.ddms.feature.group 16.0.1.v201112150204-238534)
Software currently installed: Eclipse IDE for Java EE Developers 1.3.1.20100916-1202 (epp.package.jee 1.3.1.20100916-1202)
Only one of the following can be installed at once:
Eclipse UI 3.6.1.M20100826-1330 (org.eclipse.ui 3.6.1.M20100826-1330)
Eclipse UI 3.6.2.M20110203-1100 (org.eclipse.ui 3.6.2.M20110203-1100)
Eclipse UI 3.6.0.I20100603-1100 (org.eclipse.ui 3.6.0.I20100603-1100)
Cannot satisfy dependency:
From: Android DDMS 16.0.1.v201112150204-238534 (com.android.ide.eclipse.ddms.feature.group 16.0.1.v201112150204-238534)
To: org.eclipse.ui 3.6.2
Cannot satisfy dependency:
From: Eclipse IDE for Java EE Developers 1.3.1.20100916-1202 (epp.package.jee 1.3.1.20100916-1202)
To: org.eclipse.epp.package.jee.feature.feature.group [1.3.1.20100916-1202]
Cannot satisfy dependency:
From: Java EE IDE Feature 1.3.1.20100916-1202 (org.eclipse.epp.package.jee.feature.feature.group 1.3.1.20100916-1202)
To: org.eclipse.platform.feature.group [3.6.1.r361_v20100909-9gF78GrkFqw7GrsZnvz0JWNTeb6fue6896L]
Cannot satisfy dependency:
From: Eclipse Platform 3.6.1.r361_v20100909-9gF78GrkFqw7GrsZnvz0JWNTeb6fue6896L (org.eclipse.platform.feature.group 3.6.1.r361_v20100909-9gF78GrkFqw7GrsZnvz0JWNTeb6fue6896L)
To: org.eclipse.rcp.feature.group [3.6.1.r361_v20100827-9OArFLdFjY-ThSQXmKvKz0_T]
Cannot satisfy dependency:
From: Eclipse RCP 3.6.1.r361_v20100827-9OArFLdFjY-ThSQXmKvKz0_T (org.eclipse.rcp.feature.group 3.6.1.r361_v20100827-9OArFLdFjY-ThSQXmKvKz0_T)
To: org.eclipse.ui [3.6.1.M20100826-1330]