Don’t get me wrong, I love my BlackBerry, and I love the international coverage I can get from my carrier. But there’s one little feature that bugs me.

On a recent trip to Rome, I twice had my magnetic hotel key fail. The concierge finally told me not to put my key in the same pocket with my cell phone. About that time, I also noticed a Eurocent coin firmly attached to my BlackBerry’s holster.

There’s a magnet in the BlackBerry holster that not only attracts coins but also can erase magnetic hotel keys. A little Internet research revealed that it can also erase some other magnetic cards, such as gift cards, even if they’re in your wallet but in the same pocket as the holster.

Credit cards, apparently, are made of stronger stuff. Apparently, the difference is that keys, gift cards and other cards intended to be updated have a more flexible, and more vulnerable, magnetic setup.