Im using same OS version when I got this from TMO back in September 2010 (18.104.22.168) and
have never attempted update or make changes.
(Until I read something solidly tested and proven working)
So never updates your device is my advise to all BB users but of course always a user's choice / option on this, One's prefer!
It's not my BB 9900 setting that matter, TMO currently working on portal pop-up hotspot home page / url once the setting detected from user's action on using the wifi / hotspot ( whatever that prompted the default home page to display for more information on Charge, Click Next or press enter, LOl!) it didnt happen to me' yet!
All BB devices will get the same treatment sooner or later, as TMO, they've done on the android phones devices ONCE they've tested with the "updates" roll out next from BB and for all TMO subscribers.
Don't judge or ask me where / how I learned the info and my point of view and i have no intention in challenge any experts nor disrespecting the users at this forum