InitSandboxPIBrokerIPCChannel Failing

After numerous attempts to get my plugin working I have done back to basics to full understand how the Broker Process works, so I compiled SampleExtn solution, copied the client into the plugins directory and the Broker into the pi_brokers directory, however when I try and run the menu options of the plugin, it the call to InitSandboxPIBrokerIPCChannel is failing, with no message.

How do I debug this? Is there any common things to check up?

(Am testing it with Adobe Reader IX (it IS reader enabled).

Thanks

D