Thanks for all the tips everyone. Again, I really appreciate your time.
I'm the only user on this PC, so I'm dong it with Admin rights (I assume). Unless you mean something else, like there's an 'Admin' mode I can run A:M under?
Thanks for that, and the rest of your comprehensive reply. Yes, I can appreciate that CG is going to allow me to rework and refine the performance incrementally, rather than try and nail it out of the gate. I suspected that the auto-generated lip synch would be hit and miss (there's something similar in 2D), and that I'd need to tweak it afterwards - if scrubbing through the timeline and finding the mouth movements that best fit the sound/performance is a better method, I'm more than happy to try that out.
I can open it, and I can see the phenomes. Interestingly, I still couldn't hear anything in the file you sent me (until I worked out what was wrong, see below). I could see the phenomes though.
It I try to add another dope sheet within that file, however, I get the same result of it crashing. So, it really does appear that generating the dope sheet is what crashes me out. An already generated dope sheet works just fine.
So, the above didn't directly do anything to fix this (the suggestion was to adjust the volume in the mixer - I could see the volume level was right up, and see the little bar moving up and down as if it was playing sound, but could hear nothing).
However, that thread led me here...
Which did at least solve the sound issue for me. If I go to properties and reduce the volume to 99% it works fine.
So, in short, the dope sheet feature is still inaccessible for me, but at least I can now hear sound and can therefore try and lip synch with the newer method that's been suggested.
Thanks again for everyone's help.