if you are using the original jtag wiring (are you using it?

??), you will want to try component, as HDMI gives a hell of errors (far from not working with xell, even the hacked dash will not boot 8 from 10 times)...
If you are using the new aud_clamp method, you should have patched the smc with smc_io, no problems in hdmi, but still no luck with xell(ous).