Hi!
I have exactly the same problem!
First it showed also the error 05, and it didnt run xenium OS neither any CD/DVD.
so I install an aladdin advance and it worked perfectly, and I was able to lock the HDD.
after that i re-installed the xenium again, and now my xbox always goes to the original xbox dashboard. I tried putting on the xbox with the power and the eject buttom.
I´m completely sure that my D0 point is perfectly soldered (i tested it with an aladdin advance), so I do not know what the hell can be the problem.
PD: i do not know if xenium needs, let´s say...'more contact' with the D0 than aladdin advance, but I guess not.
I think this problem is realated with the solder-mode, If i remember well my friend told me that his console was working fine with the solderless adapator, but he had always to readjust it. and anyone know whyyy there is no tutorial about xenium ICE in ozxodus site??? it´s amazing!!