The computer will recognise the phone as a portable device, because that's how it's been connected and the only way PC Suite can find it to backup or edit it. If you connect in mass media mode, the computer will see it as an external storage device, this is normal, don't worry about it. It's Microsofts way of interacting with the phone, you could , for example sync your media using WMP with phone connected in PC Suite mode.
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