For those needing to get their Vodem working on 64 bit version of Vista, there is now a solution. This is not released officially yet, so keep in mind there may still be bugs / issues / non support from Vodafone etc.

Step 1. go to vodafone.co.nz and get the Vodem Vista update, follow through the instructions to update the firmware etc of the Vodem. This must be done on a Win XP machine. Do NOT plug the Vodem into your Vista 64 bit machine yet.
https://www.vodafone.co.nz/personal/plans-services/3G-broadband/vista-support.jsp

Step 2. Download VMC version 9.1.2, either Google this, or send me a PM for the link. (I won't link here as I don't think the website has been publicised, nor have I asked permission to post in public forum).

Step 3. Install the new VMC software on your Vista 64 machine (don't use optimised settings) & reboot

Step 4. Plug in Vodem to Vista 64 machine. Wait for autorun and driver install. Close any autorun boxes etc

Step 5. Open VMC software you installed and setup your Vodem. Choose the "Vodafone Mobile Connect Card" option. It should soon recognise your Vodem and install a few more drivers.

Happy Vodem'ing

This may also work for a few other Vodafone cards too, but i have tested others yet.