Hello,
the question is not V.35 versus SHDSL but how the service is configured and what encapsulation is expected:
bridging over frame relay is possible but it is a different encapsulation from sending IP packets inside a FR frame:
IP over FR = FR | IP
bridging over FR = FR | ethernet | IP
if you send the second one and the other device expects the first there is no match.
Hope to help
Giuseppe