Channels and busses randomly re-routed in Logic 9?

Question

Is this happening to any one but me?  It's kind of difficult to artculate but here goes.  Scenario:  I have several Logic sessions (projects started a while back) that all have similar random issues.  The projects were started as new blank or from a template.  They've been updated, saved, re-opened and re-saved and re-opened dozens of times.  Over time, I've added new tracks, Aux sends and returns (aux channels w busses assigned).  There are plug-ins on all the tracks, some Logics some Waves or other vendors.  I've edited and comped - all the types of normal updates.  The tracks contain audio regions, loops, MIDI instruments, stuff like Superior Drummer or EX synths.  I have backups and versions of all these versions.  Some were started with a MOTU travelor, some with an MR816, and I've added a UA 4-710d recently.  This behavior spans all of it. 
I'm now mixing.  Every time I re-open one of these sessions (projects), I find more bizarre, seemingly random changes.  There's a stereo audio drum track- it contains a mixture of audio regions, identical copies; others are unique regions (a track of drum loop patterns with a few fills, for example).  When I last saved this session the track was fine, stereo, all regions played back.  The next time I opend the file the "fills" regions were silent.  I opened them in the Finder and they soun fine.  OR the track is no longer Stereo and the sound is only on one side.  Or the Inspector to the left of the Arrange Window is blank, and right clicking on the channel reveals that the track (let's say "track 2 drums") is "Controlled by track 19," which is a MIDI track.  My solution is to create a new track and re-copy the slient regions from the finder. Now I have two drum tracks.       
I set up three aux busses, one for Delay, one as an ambience compressor, and one with Space Desgner. I re-open a session and the Aux returns no longer show the signal coming from a Buss, but now from an input.  I reassign them and I'm ok.  The plug-ins still same as before.
But this rerouting is very confusing. Nothing changed in my hardware from the last to the next session.  For me, even if hardware is changed the internal routing should not. I can see about inputs but not an Aux or Stereo mix bus.  What happens when I take my session to a studio to mix?  They have a totally unique system and configuration.  I was advised to turn off and disconnect everything external in order to get to a vanilla configuartion.  So did so and used Apples internal line in (even though I'm no longer recording) and The headphone out.  (Mac Pro 8-core).  Same thing.  The tracks are still moved.  I even see tracks that are nto stereo nor mono.  There a tracks with no stereo assignment at all (below the strip meter, which is single nto separated), even a track showing two circles NOT overlapping, one is dark and the other open / white.  I right-click and see the options Stereo, Mono, Surround.  sound comes out one side. Bizarre!
My only way to deal with this - since I've got a month invested is to create a new track for each of these- and it's working so far.  But I can't imagine haiving to keep doing this.  I trashed my Logic Preferences. I asked about a Logic cache - none such exists.  If I was working in Cubase, for instance, I'd see a VST Connections Window.  And one for Devices. I could completely reassign everything.  Is there no such control in Logic?  Is this a Logic issue or Core Audio?
I have a radio spot music bed that was starte in Logic a few versions back.  I've noticed similar behavior- and solutions - a few times.  A guitar track goes silent. I copy it to a new track and it's ok, and then a MIDI drum track goes south.  I thought this was because it was started on a differnt Mac.  But then I think - so what?  These projects should be futre compatible- even if it takes some re-sassignments. 
Can't figure out why this happens or how to fix it. 
Anyone have any thoughts or ideas - or similar behavior?       

Answer 1

Last things first... Sorry, no, I can't read crash reports. I'm better at reading Japanese, honestly. However, I've encountered the same error before:
EXCBADACCESS (SIGBUS)
...and if you do a google search you'll see that you're not alone, and, that it's not limited to working in Logic. Of the first hits on google someone said that it's a sign of bad RAM, but there were many other links to investigate so I would take that with a grain of salt for now. Maybe do a search for that yourself and see if anything posted on the web hits home for you.
EXS24 settings -- I just wanted to see if VM was on or off.
Interesting that it doesn't always happen. OK, are there particular libraries (3rd party, Logic factory stuff, etc.) that seem to perpetrate the crashes?
In the song(s) you're experiencing this in, are they already very sample-intensive, lots of sampler instruments loaded up? The reason I ask is that Logic has been known to go "huh?" and quit unexpectedly if you attempt to load up more samples than can fit into Logic's RAM footprint.
Another test... does this happen in a brand new, empty song (such as the Explore/Empty template)?
There are more things you can do to try and narrow down the problem, but rather than overwhelm you with stuff I'll stop here. Post back with your answers/results and we can take it from there.