The easiest way to enable yourself to become root is to add the repository described here and installing the becomeroot package.
Also install xterm if you haven't yet.
Once you've installed the becomeroot package, run xterm and enter:
sudo su -
Your prompt should end in #
That indicates you're now the root user. If it ends in $ then you're just the normal user.
Now edit the /etc/bluetooth/rfcomm.conf file as described here .
Change the mac address in maemo-mapper's settings to /dev/rfcomm0 and reboot. Your GPS won't get "lost" anymore and you won't need set the escape key to reset the bluetooth connection. You can use it to toggle between street maps and satellite maps or whatever.

If you don't know how to edit a text file in linux, you can copy the file to your mmc card then connect the usb cable to your PC and edit the file with a PC editor then copy the file back to where it belongs:
as root enter in xterm:
cp /etc/bluetooth/rfcomm.conf /media/mmc1
Connect the USB cable and on the PC edit the file then disconnect the USB cable and:
cp /media/mmc1/rfcomm.conf /etc/bluetooth

If that seems too difficult, post your GPS's mac address and I'll post an edited file for you.