Motorola SLVR L7

There's no way that the SLVR can hold little more than 17 text messages. Why does my SLVR say "Messages Full" when I have no text messages on the phone and 17 on my SIM card? For clarification, the SIM card that I am using is an older one that I got from Cingular probably two years ago. Would that be the reason? Are new SIM cards from Cingular of higher capacity, and thus able to hold more than 17 text messages? Or is there some sort of ridiculous limitation on the SLVR that will allow messages to be stored only on the SIM and/or not at all on the phone?

Also, I am baffled by the SLVR's phonebook. I have had a Motorola phone in the past and I know pretty much how to use it, but I honestly don't know how to be able to use speed dialing on...
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