Help! Following a crash/froze/kernel panic while video editing, I've "lost" an iMovie Project!

Question

I've been using iMovie for a number of years in all its various versions from about iMovie 4 onwards.
For the past year while I've been using iMovie 9, about once a day my iMac has periodically experienced a crash/freeze/kernel panic - ie the screen goes grey - ie "grey screen of death!", (sometimes with horizontal lines on it at intervals) and the GUI becomes totally non-responsive; when this happens I usually have to cycle the power and do a cold restart.  In every instance, my iMovie Project has remained more-or less in tact (perhaps with the most recent change missing, but that's usually easy enough to redo).
Last week, I upgraded iMovie 9 to 11 and I've continued editing for several days and until tonight (fingers crossed) all seemed well - no crashes!
But ealier this evening, while editing, my iMac experienced another crash/froze/kernel panic; on reboot, I discovered that my current Project has disappeared completely from iMovie's Project Library!  Using the Finder I can see that it is STILL there on the HD - I can open the .rcproject package and the Project file is inside!  I tried double-clicking on the Project file and sure enough iMovie 11 launches, but there is no sign at all of my Project in the Project Library. 
How can I recover it so that I can continue editing? 
VERY fortunately just yesterday I exported the entire Project as a HD Movie to view on my TiVo, so I've been able to re-import that movie back into iMovie, so I've lost very little.  But I have have a number of Projects on the go and I don't want them all to vanish one-by-one!
If THIS is one of the new features of iMovie 11, I want my money back!

Answer 1

After receiving a deafening silence to my original post, I contacted the "geniuses" at Apple. 
I'll cut to the chase - they could do nothing for me; apparently my Project is probably corrupt and that's why it no longer works.  They could offer no tools that I could use to check and correct the corrupted Project, just basically said "tough". 
Along the way they suggested that I should trash my iMovie preferences which are found as follows...
Macintosh HD/User/Library/Preferences/com.apple.iMovieApp.plist
(Note "User" is whatever you log in as).
Problem was that my iMovie 11 just returned to as it was when it was first installed (without fixing my faulty Project!)  Actually, that was a bit of a problem because I could no longer switch my video to my second monitor because the "Viewer on other Display" was no longer the last item under my iMovie's "Window" menu item.  It took me a little while to discover that I had to check the "Show Advanced Tools" in the "General" Tab of "iMovie Preferences" for that and other features to become available again.
So, I'm sorry, I have nothing to offer you that shows any promise - apart of course from regularly backing up the Project onto another drive (which is what I now do)!