FCPX 10.0.9 project AND events load then disappear

I've put all media, event and project files on a 1TB external FW800 drive and now I am unable to edit. FCPX shows the media and project files BRIEFLY then they disappear, drive and all.
Does anyone know what could be causing this? I've tried on 2 machines with the same results, I've restarted with and without drives attached, I've rebooted machine and still cannot understand what would be causing the drive to be rejected.

Any others with this experience?
My Google search had a few suggestions found but nothing worked for me.

Thanks
Hugh

What did you find and what have you tried?

I just re-read a CC post found here:
forums.creativecow.net/thread/344/21062

Something I overlooked was a line that read "it appears that there is still something on that disk that's identifying it to FCP X as camera media"

I then realized I had a DCIM folder from my EOS in the root, I deleted it, emptied the trash and reopened FCPX.
It worked!!

Thanks Tom! I wouldn't have revisited that page had you not asked that question.