ADE 3.0: E_ACT_NOT_READY error - what does it mean?

Hi knowledgable and helpful Adobe forum people,

I'm getting an E_ACT_NOT_READY error when trying to open an ebook I just purchased and downloaded.

Backround:

I've had an Adobe ID for several years and bought several Adobe ebooks from various retailers and generally access the ebooks on desktop (I know - wierd), I just got a new MacBook and want to move some books across, and buy some new ones.

What happened:

- I installed ADE 3.0 on my new MacBook (I didn't get a prompt to authorise my computer and there doesn't seem to be an option in the menu to do this retrospectively)

- I've paid for and downloaded an ebook in the form of a 1KB ASCM file

- I go to open the ASCM file

- I get an E_ACT_NOT_READY error when attempting to open the new ebook I just downloaded, as well as other ebooks I have in my library:

Questions:

- Is anyone else getting this error?

- Has anyone found a solution / workaround?

This is REALLY frustrating - any assistance from Adobe or anyone on what might be causing this much appreciated.

Thanks in advance.