Get your hands on a 1.4 cable and try that. I'm not sure if two 1.4 endpoints can easily talk over a 1.3 cable
Physically speaking, HDMI 1.0 and 1.4 have the exact same pinout so there is no mechanical or metallic continuity reason for HDMI 1.4 devices to fail to connect over older cables.
Depending on how long the cables are, the quality of connectors and the cable itself, signal integrity may become a problem. Over short distances such as the typical 3-6' in most AV setups it should still work unless there is something fundamentally wrong with the cable.