The steps outlined worked for me...
A few things for my Atrix I noted, and I guess I was lucky that my blind faith in this community worked!
Here are the steps I took... hope they help put your mind at ease!
- Pre-AT&T Update: I had a rooted atrix 4g 4.5.91 using SuperOneClick
- I accidentally pressed "yes" to AT&T's OTA update w/o realizing I would lose my root.
- panicked and searched all over the web for a way to root
- found this thread and followed the advice verbatim (actually followed the original post, and used this post to verify as well as to glean insight from others' experiences)
- While following the steps verbatim, my phone never reboot itself... so I just pulled the battery
- after turning on the phone, simulating a "reboot" with the battery pull, I ran the adb scrpts.
- I also ran into the first "error" and kept going like Dark9781 suggested
- towards the end, I couldn't install the SU (cp /preinstall/su /system/bin/) because one was already installed (I saw that the OTA update didn't remove the SU App)
- Checked if my phone was rooted anyways using Titanium Backup
- the current SU I had reported that it was out of date, but the phone was still rooted