How can I diagnose a Labview RT program crash on cRIO 9073?

Question

I have 2 cRIO 9073 purchased about 1 year apart.  Both are running the same realtime application.  The first cRIO runs fine.  The 2nd cRIO crashes intermittently while executing 1 particular VI that contains 2 timed loops running in parallel (1 collecting data and the other controlling machine movement).  When it crashes, the app stops, web server and FTP stop responding, MAX cannot communicate with the device ( I must perform a hard reset).  After reset, viewing the error log using MAX shows no errors.  I've added message logging to see if it stops in a particular place, but see no patterns.  In some cases, the device seems to be continually restarting (every 2-3 minutes) until it finally hangs.  In many instances, my configurations files (used to store runtime variables) have been corrupted or erased.  When trying to deploy the app on this Rio, I generally must try multiple times because I receive the error, "Error deploying on target".  I have tried formatting the flash and reinstalling the OS many times from different sources.
I'm running Labview 2009, SP1 with the FPGA option. 
Any ideas on how to diagnose this problem?  Are there any diagnostic tools to test this device?

Answer 1

Here's a better description of what I'm trying to do.  This system is used to control the head position on a test machine.  I used the LV RT wizard to create the base VI with 1 deterministic loop and 1 non-deterministic.  The deterministic loop schedules 2 different test.  Test 1 is every 5 minutes (collect analog data, read temperatures, calculate new head position based on temperature , drive stepper motors to new position, collect data after moving, then dismiss).  Test 2 runs once a day with a duration of about 4.5 hours (drive stepper motors to user defined position, simulatiously collect data at various rates from 5Hz to .01 Hz, drive head to next user defined position, etc). This test has 2 timed loops running at different rates, one collects data, the other moves the head and acts as a timer to know when to move to the next position.
If I never run test 2, then the system has never crashed, leading me to believe the problem is in the test 2 VI.  The crashes don't necessarly occur in the Test 2 VI.  On some occations 1-2 hours after Test 2 has completed, the CRIO will start rebooting itself (every 2-3 minutes).  This may happen 4-5 times until it will finally hang completely. 
Since the crashes happen randomly (it may run for 2-3 days before crashing) I'm trying to find some way of trapping  errors or exceptions that would give me some clue as to what the problem may be.