My game generally hates new stuff, I have a gaming machine that should in theory be able to handle TS3 and then some more. Yet every time I attempt to install something new (world, content or patch), it looks at me as if to say 'pah me work, I think not'. The only way around this that is to start from the top. Uninstalling all my custom content (EA or otherwise), then trying to install. If that doesn't work I try the new fangled time saving factory reset. If that should also fail me I start from the very beginning, cursing TS3 to the moon and back. After a complete uninstall I always perform a disk clean up, a registry clean, a scan disk and a defrag. Ideally you should also do a disk clean up, scan disk and defrag after installation too, but who has time for that? lol
Lastly install all your custom content (EA or otherwise) and save files.
I have never failed to install my shiny new things using this method.
Kindest Regards
KJ