FCPX has suddenly started crashing when trying to import media

Question

I updated FCPX to 10.0.8 a couple of weeks ago and everything has been fine until today (I'm fully updated with Mountain Lion as well) .  Now every time I try to import media, FCPX crashes. This occurs right after I hit the "Import Selected" button -- and occurs regardless of type of media, where I'm importing it from, or how many clips.  I get a very long error message -- I've attached just the first part of it (through Thread 0) below.  The entire error message runs through Thread 37.
The only thing I did right before this happoened was to delete some old unused applications that were not even on the system HD (they were on a different internal HD - drive A).  The applications included very old versions of Final Cut and iMovie that had not been opened in a couple of years.  After I did this, FCPX suddenly started to recognize another internal HD (drive C) as a camera for the first time, and tried to import a bunch of old home movies, which it has never done before.  And ever since then it started crashing when trying to import new media -- even after I "ejected" drive C. 
Any ideas?  I'm at a total loss and in the middle of a big project for a client, and could really use some help.  Thanks!
Process:         Final Cut Pro [326]
Path:            /Applications/Final Cut Pro.app/Contents/MacOS/Final Cut Pro
Identifier:      com.apple.FinalCut
Version:         10.0.8 (221398)
Build Info:      ProEditor-22139008018000000~1
App Item ID:     424389933
App External ID: 14685451
Code Type:       X86-64 (Native)
Parent Process:  launchd [152]
User ID:         502
Date/Time:       2013-03-31 13:00:19.713 -0400
OS Version:      Mac OS X 10.8.3 (12D78)
Report Version:  10
Interval Since Last Report:          14013 sec
Crashes Since Last Report:           9
Per-App Interval Since Last Report:  12180 sec
Per-App Crashes Since Last Report:   9
Anonymous UUID:                      11BDDCCB-5BCF-05B8-C04A-9A39067B1572
Crashed Thread:  0  Dispatch queue: com.apple.main-thread
Exception Type:  EXC_BAD_INSTRUCTION (SIGILL)
Exception Codes: 0x0000000000000001, 0x0000000000000000
Application Specific Information:
objc[326]: objc_removeExceptionHandler() called with unknown alt handler; this is probably a bug in multithreaded AppKit use. Set environment variable OBJC_DEBUG_ALT_HANDLERS=YES or break in objc_alt_handler_error() to debug.
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   libobjc.A.dylib                         0x00007fff8d168814 objc_alt_handler_error() + 0
1   libobjc.A.dylib                         0x00007fff8d1686a0 alt_handler_error(unsigned long) + 52
2   libobjc.A.dylib                         0x00007fff8d162f35 objc_removeExceptionHandler + 92
3   com.apple.CoreFoundation                0x00007fff893ebb49 _CFDoExceptionOperation + 89
4   com.apple.AppKit                        0x00007fff86e2bbcf -[NSApplication endModalSession:] + 24
5   com.apple.prokit                        0x00000001003283c3 -[NSProApplication endModalSession:] + 45
6   com.apple.FinalCut                      0x0000000100033870 -[PEAppController windowWillClose:] + 416
7   com.apple.CoreFoundation                0x00007fff893aceda _CFXNotificationPost + 2554
8   com.apple.Foundation                    0x00007fff8575ae26 -[NSNotificationCenter postNotificationName:object:userInfo:] + 64
9   com.apple.AppKit                        0x00007fff870c49e0 __18-[NSWindow _close]_block_invoke_0 + 260
10  com.apple.AppKit                        0x00007fff870c48b5 -[NSWindow _close] + 364
11  com.apple.FinalCut                      0x0000000100073be7 -[PEImportWindow timer] + 439
12  com.apple.Foundation                    0x00007fff85785af3 __NSFireTimer + 96
13  com.apple.CoreFoundation                0x00007fff893b7804 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 20
14  com.apple.CoreFoundation                0x00007fff893b731d __CFRunLoopDoTimer + 557
15  com.apple.CoreFoundation                0x00007fff8939cad9 __CFRunLoopRun + 1529
16  com.apple.CoreFoundation                0x00007fff8939c0e2 CFRunLoopRunSpecific + 290
17  com.apple.HIToolbox                     0x00007fff84842eb4 RunCurrentEventLoopInMode + 209
18  com.apple.HIToolbox                     0x00007fff84842c52 ReceiveNextEventCommon + 356
19  com.apple.HIToolbox                     0x00007fff84842ae3 BlockUntilNextEventMatchingListInMode + 62
20  com.apple.AppKit                        0x00007fff86f2e563 _DPSNextEvent + 685
21  com.apple.AppKit                        0x00007fff86f2de22 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 128
22  com.apple.AppKit                        0x00007fff86f251d3 -[NSApplication run] + 517
23  com.apple.prokit                        0x00000001003286c5 NSProApplicationMain + 378
24  com.apple.FinalCut                      0x0000000100001e14 start + 52
I'th Mountain Lion as well.  *and FCPX 10.0.7

Answer 1

Update: the problem is definitely with the internal HD "drive C".  Before restarting FCPX after the last crash I unmounted the C drive -- then restarted FCPX and was able to import media just fine.  I thought I had tried this already, but I guess not.
So, what did I change with my C drive when I deleted the old apps off my A drive?  There is both an iMovie events and projects folder on the C drive -- but FCPX has never tried to import them until after I deleted the old iMovie app (I still have the most recent version of iMovie on my system drive -- but have never used it to open these old folders).  I read on another thread on this forum that if I "hid" these folders, FCPX would not try to recognize them, so I moved them to within another folder on the same drive -- but FCPX is still trying to recognize and show them when the Import Media window is launched --  and still shows the C drive as a camera.
So, what can I do to stop this from happening?
Thanks!