passing user defined data types to stored procedures

Does the driver support passing UDTs as arguments to stored procs?

Suppose I have a class Foo that implements SQLData.

On the server side, I've created a composite type called "foo", along with a proc that accepts a single "foo" argument and returns a "foo".

On the client side, I acquire a connection and set its type map such that "foo" maps to Foo.class.

When I try to setObject(2, new Foo()) on a CallableStatement, I get that the driver can't infer the SQL type to use for an instance of class Foo.

Have I screwed something up, or is this just not supported?  The driver docs didn't have much to say, that I could find.