since you are from US, i hope it's not a big deal if i reply to you in english, just doesn't know how to type chinese on a keyboard.
About the sim hack, if you are using t mobile, then i would suggest you to try NextSim v6, or v7, it's the most stable on t mo that i know of. If you are using att, i dont really suggest you to use keitai at all, since a lot of their radio band is on 850mhz, and most of the keitai is only triband without the 850mhz band. Oh, and i'm using a p905i and so905i on t mobile. Try howardforum, if you are from US, there is a lot more people on their that use keitai that are from either US or Canada.