Spent 45 minutes on the phone with Apple Support to learn that iOS 5.1.1 has a limitation of 11 screens as application containers in the iPhone 4.
I usually go to Settings -> General -> Reset --> Reset Home Screen Layout so all my applications are ordered alphabetically. I don't like app folders.
Noticed that the Comcast Email app "XfinityConnect" was no longer in the last screen but I am able to find it using the Spotlight search when you press twice the home button, and I am able to use it without any problem.
Also noticed when I have the iPhone 4 connected to iTunes 10 on my MacBook Pro there are only 11 numbered thumbnail screens showing my apps organized as I have them in my phone with a black background and there is a 12th screen showing all the apps I have in my phone that are not displayed (Xfinity Connect, Xfinity TV, Y! Messenger and YouTube) with a grey background.
A bit frustrating calling Apple Support, the first advisor wanted me to contact Comcast because they developed the apps. I requested to speak to somebody else and I got a "Senior" advisor who as one of the last steps wanted me to remove all my applications losing all the customization. I refused to do it stating that I'd lose all my customizations for all my 100+ apps. After she took 5-10 minutes to research the issue, she finally acknowledged my iPhone 4 was behaving the way it is supposed to. She didn't accept the fact this was a "bug", this is "normal" behavior.
Isn't Apple support wonderful?
A bit frustrating ... I should have used Google first. Google is your best friend!