I'm on Sprint, but my phone went through 2 updates. I think the first one had 10 steps and, when that one finished, it was 7.10.xxxxxxx. The second one had 9 steps and, now, I have 7.5.
I did not have a third update. I had two ten-step updates and ended up with Mango. It took about 2 1/2 hours.
It still shows the same OS Version as RTM: 7.10.7720.68
So what does that mean? I'm guessing ATT did not make any changes to RTM they got from MS? The same RTM I have been running?
In the About screen, mine says "Software: Windows Phone 7.5", and below that "OS Version 7.10.7720.68".
AT&T in Dallas, Samsung Focus, went through three updates at lunch today.
Could you please verify what your OS Versions says? settings/about/more info/OS version. I have 7.1.7720.68