What error did you get when trying to install via the new web client? to be able to deploy OVF's etc (in the 5.1 release) you need to be running the browser via a windows OS. If you are running OSX then you cannot install the web client integration plugin (linked of the web client login page bottom right hand corner) which means you will not be able to deploy OVF files etc.
If you can login to the web client navigate to Administration > Plugin Management and you should see a "vSphere Replication" plugin with an "Enabled" state. If you do NOT see that you've deployed the OVF/A incorrectly or not done it via vCenter.
