I can "second" the cell phone may interfere with the cargo supression system, as I have also flown that a/c. Also, I know for a FACT that the iphone when searching for a signal WILL interfere with our communications. There is an annoying and somewhat loud buzz and ticking noise in the background. This also happened with those annoying nextel walkie talkie phones.

The bottom line is... JUST FOLLOW THE RULES. And again... there may be slight variations to all the policies depending on which airline you're flying on. Again... with EIGHT connection partners and mainline, that brings NINE manuals and nine approvals from the FAA. They're not all exactly the same. So before you go blaming the FA for being lazy, overbearing or poorly trained think about the reasons behind why things are done. Or, just forget about WHY things happen and just follow the rules.