the problem seems to be that Plone 4.3 is expecting plone.registry to be installed and that package was not available in Plone 3.3; I already answered that to you before here in the forum.
I was checking the Plone Upgrade Guide but I can't find any reference to this.
please try the upgrade i smaller steps: first upgrade to Plone 4.0, then to Plone 4.1, and so on; seems to me something is missing but I have no idea where.