While I have never modded my xboxs personally, I have a friend that can solder (thats the only thing I don't know how to do ).
So I got this free Xbox v1.0 and I got my friend to mod it. He uses Xecuter 2.6 chips. He worked around the problem the initial bios has with early xboxs (Something about the video coming up black otherwise). I can't remember what he mentioned about it.
Anyway, After he flashed it to a reasonably recent bios it worked fine, he put in my 80 gig western digital drive and all was well.
One thing he did mention to me though is that when the xbox is coming form a cold boot (turning on after a while of being off) we have to power it on and off a few times (sometimes up to ten) before it will boot to the bios. After it boots, when you try to run a game (at least off the hard drive) it freezes most of the time. When it doesn't, the xbox runs fine.
I have been told this is a common problem but I haven't found an ounce of information on this thing. Excuse my ignorance if it is common, but what should I do? Is it not injecting the bios fast enough? Do I need a newer chip?