Recently one of the Forefront Identity Manager Engineers, Michael Smith ran across an issue with an Oracle MA.
It was determined that the root cause of the issue was an issue with the 11g client itself.
More information on the Oracle side of the issue can be found here.
After creating the Oracle MA using the 11g client, FIM indicates that it cannot see the 11g 64 bit installation of the administrator client. The existence of the client on the FIM Server can be tested by creating a UDL (Universal Data link) file.