Tunnel failure could mean that you need to specify your APN Settings.
Go to Options > Advanced > TCPIP and add your APN settings there.
Look at
Carrier APN Settings - ModMyi - Wiki or
APN Settings for iPhone 3G | The iPhone User Guide for APN settings related to your Carrier (Digicel)
Another SSH Client that you can use is Padersync available at
PaderSync Home but it costs 29.99$ i recall it used to be free but have a look.
Cheers