10.0.6 Projects/Events on External Drive Issue

Ever since the update of 10.0.6, I seem to be having an issue with the projects that are stored on my external media. They are no longer shown in the project manager (infact one of the storage devices flashes up with the project but then it dissapears instantly). Not only that but when I come to "Duplicate Project" or "Move Project" FCPX no longer recognises the external devices as an option.

A little more info:

- I am testing on my Macbook Pro (13-inch, 8GB RAM, i5, one prior to the Retina) and my iMac (27-inch, 8GB, i5, prior to the newest one)

- I am testing two external storage devices (SD card and USB HDD)

- Both devices are recognised by the new Media Import feature AND Finder

- Occasionally flashes up project once in the Project Manager

- Both Macs updated to the latest FCP update

- Both Macs are running Mountain Lion

Has this feature been moved/removed? Do I need to do something different now? Is there a work around apart from manually copying over projects/events?

This was a really useful feature for me as it meant I could just use external storage and switch between computers.

Thanks for your help,

Mike