Hi Towser,
Sorry to hear you are having difficulties, but I'm sure we can help you solve it. There are a few things that can cause this problem. Check these things in this order.
1. Make sure that you are installing the latest drivers for the TranzPort from our website downloads page. The older drivers on your original CDROM may not be Intel Mac compatible. http://frontierdesign.com/Support/Downloads/TranzPort
2. Be sure to run the TranzPort Installer from inside the folder it comes in. This folder also contains the "Remover" and a hidden folder with all of the component files. If you drag the Installer out onto your desktop alone than it can't find all of the support files to install.
3. Repair Permissions. This should be done periodically anyway. Go to MacHD/Applications/Utilities/Disk Utilities. Launch Disk Utilities and select your system HD on the left, then click on "Repair Permissions". Then restart. It may take a few minutes to run.
4. Open the Mac AudioMIDI Setup panel, also in the Utilities folder. Click on the MIDI tab and in the "Configuration" menu select 'Create' new. This will force the Mac to rescan all MIDI devices.
One of these things should do the trick. Let us know how it all works out.
CS