installing tomtom mobile on Tungsten T3

Hi
I have a Tungsten T3, but can't seem to access the SD memory card, to install tomtom mobile.

What is the method to install applications from the memory card?
Should the contents of the card be displayed when the card is inserted?
Am I missing any software on my palm to access the card?

When I insert the card, I get a 'bleep' and the card is recognised when I click the 'card info' icon..it gives me the card type, size..etc, but I don't know how to access the contents of the card to run the applications..

Your help would be much appreciated.
Thanks in advance..

Andy