A few hours ago Smartone-Vodafone's (SMV) IOM Toolbar (the thick red bar at the top and bottom of browser window) returned to the Safari browser on the iPhone. I called SMV Customer Service and they say the issue has to do with a system upgrade which failed to honor the flag, "Disable IOM Toolbar".
This has to be the third time such issue occurred. I don't think any iPhone users will ever want the SMV IOM Toolbar occupying the valuable Safari browser space. So the correct way to disable the IOM Toolbar is to check the browser's User Agent rather than some flag in a customer's profile.
I agree that the IOM Toolbar may be useful for traditional mobile phones which do not have a full browser, but even phones using the Opera mobile browser will not need the IOM Toolbar.
For all "smart phone" users the IOM Toolbar should be opt-in rather than opt-out.