Cannot infer transport with libcurl enabled

With libcurl enabled, some of the samples fail in trunk, with a message that says: "Cannot infer transport from URL"

samples/client/amqp/echo/echo_blocking

[Mon Feb 25 10:37:39 2013] [debug] phase_resolver.c(722) Module name is:addressing
[Mon Feb 25 10:37:39 2013] [debug] phase_holder.c(131) Add handler AddressingOutHandler to phase MessageOut
[Mon Feb 25 10:37:39 2013] [debug] phase_resolver.c(722) Module name is:addressing
[Mon Feb 25 10:37:39 2013] [debug] phase_resolver.c(722) Module name is:addressing
[Mon Feb 25 10:37:39 2013] [debug] phase_holder.c(131) Add handler AddressingOutHandler to phase MessageOut

Sending OM : <ns1:echoString xmlns:ns1="http://ws.apache.org/axis2/services/echo"><text>Hello World!</text></ns1:echoString>
[Mon Feb 25 10:37:39 2013] [debug] op_client.c(904) Start:axis2_op_client_infer_transport
[Mon Feb 25 10:37:39 2013] [error] op_client.c(962) Cannot infer transport
[Mon Feb 25 10:37:39 2013] [debug] op_client.c(965) End:axis2_op_client_infer_transport
[Mon Feb 25 10:37:39 2013] [error] op_client.c(422) Op client execute failed. Cannot find transport out.
[Mon Feb 25 10:37:39 2013] [error] echo_blocking.c(101) Stub invoke FAILED: Error code: 4 :: Cannot infer transport from URL
echo client invoke FAILED!