Eclipse eUML2 plugin installation problem and solution

Got red herring errors below when trying to install Soyatec's excellent UML Eclipse plugin eUML2.  Found real answer in the Soyatec forums here -- install GMF (Graphical Modelling Framework) first.
Worked a treat. Errors after the break.

For saving others from this minor yak, I strongly suspect these errors are red herrings -- hits from Ubuntu and Eclipse aren't useful (especially obvious since I happened to be on Windows7 rather than my usual Ubuntu this time!!!)

Error 1:

  Cannot connect to keystore.
  This trust engine is read only.
  Cannot complete the install because one or more required items could not be found.
    Software currently installed: eUML2 Free Edition 3.4.0.20091122 (com.soyatec.euml2.free.feature.group 3.4.0.20091122)
    Missing requirement: Modeling toolset 2.5.0.20091122 (org.soyatec.tools.modeling 2.5.0.20091122) requires 'bundle org.eclipse.gmf.runtime.notation 0.0.0' but it could not be found
    Cannot satisfy dependency:
      From: eUML2 Free Edition 3.4.0.20091122 (com.soyatec.euml2.free.feature.group 3.4.0.20091122)
      To: org.soyatec.tools.modeling [2.5.0.20091122]

Error 2:

java.io.IOException: This trust engine is read only.
at org.eclipse.osgi.internal.service.security.KeyStoreTrustEngine.doAddTrustAnchor(KeyStoreTrustEngine.java:154)
at org.eclipse.osgi.service.security.TrustEngine.addTrustAnchor(TrustEngine.java:50)
at org.eclipse.equinox.internal.provisional.p2.engine.CertificateChecker.checkCertificates(CertificateChecker.java:106)
at org.eclipse.equinox.internal.provisional.p2.engine.CertificateChecker.start(CertificateChecker.java:41)
at org.eclipse.equinox.internal.provisional.p2.engine.phases.CheckTrust.completePhase(CheckTrust.java:43)
at org.eclipse.equinox.internal.provisional.p2.engine.Phase.postPerform(Phase.java:195)
at org.eclipse.equinox.internal.provisional.p2.engine.Phase.perform(Phase.java:78)
at org.eclipse.equinox.internal.provisional.p2.engine.PhaseSet.perform(PhaseSet.java:44)
at org.eclipse.equinox.internal.provisional.p2.engine.Engine.perform(Engine.java:54)
at org.eclipse.equinox.internal.provisional.p2.ui.operations.ProvisioningUtil.performProvisioningPlan(ProvisioningUtil.java:389)
at org.eclipse.equinox.internal.provisional.p2.ui.operations.ProfileModificationOperation.doExecute(ProfileModificationOperation.java:61)
at org.eclipse.equinox.internal.provisional.p2.ui.operations.ProvisioningOperation.execute(ProvisioningOperation.java:37)
at org.eclipse.equinox.internal.provisional.p2.ui.ProvisioningOperationRunner$1.run(ProvisioningOperationRunner.java:94)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)

For your amusement, below is the first class diagram I've reverse engineered from [my version of] the Android SyncAdapter example.

UML class diagram of SyncAdapter