iPhone Verizon suddenly asking for userID password

I dont know if this is a Wi-Fi, bluetooth, EDGE, or what related issue. (Once when this issue happened, I saw a reference to arubanetworks.com if that sheds any light.)
At my office over the past 2 days, my iPhone 3G screen will suddently switch to a mostly-black screen asking for a userID and password. It gives no indication as to what that ID/Password is for.
I turned off Choose a Network in Settings, but that hasnt helped.
Im on 3G and there HAS been a Wi-Fi location that has popped up on-screen before, but I would just cancel that request and stay on 3G. That screen doesnt show up in this black-screen issue, though.
I have no idea if this latest screen dilemma has anything to do with Wi-Fi or what as again the screen gives no clue. HOWEVER, as mentioned above I thought one time that it happened I saw a reference to ARUBANETWORKS.COM - - again, something else Im not familiar with.
Can someone explain what might be happening in these instances and what I might change to stop it?
Thanks in advance
27" i3 iMac (mid-2010) / 3.2ghz Mac OS X (10.6.6) 8gb RAM / 1000gb intl - 1000gb extl HDs