DAQmx task does not start on RT target

Question

I cannot programmically start a DAQmx task on an RT target.  The PXI-8140RT controller hangs on either the DAQmx Start Task.vi, DAQmx Read.vi, or the DAQmx Create Timing Source.vi, depending on the level of complexity I try to use.  Any suggestions on what would cause this?
The vi running on the target is based upon the wizard created target-multi rate-variables-fileIO.vi.  I cannot stop the vi once it hangs; I can only close it.  I have to restart the controller to reestablish communication.    I have tried DAQmx tasks created using MAX, created programmically, and created from a front panel task control.  The tasks test ok using the MAX or the DAQ Assistant.  For now I am trying to measure one RTD channel. 
The RT system consists of the PXI-8140RT,  a PXI-6259 M-series controlling a SCXI chassis, and the SCXI-1102B and SCXI-1581 pair capable of measuring 32 RTD's.  There are two other modules in the SCXI chassis which aren't being used yet; a SCXI-1162HV and SCXI-1163-R.  The target and host are running LV Real-Time 8.01 and NI-VISA 3.5.  The host has NI-DAQmx 8.0.1f while the target has V8.0.0, apparently the lastest available.

Answer 1

The VI didn't generate an error message.  Nor was there a message in the RT error log.  I guess it froze before an error could be generated.  I used the DAQ Assistant Express vi in a totally new project.  I have since converted this to code and added features to make it more like my original project.  The new project is working.  I suspect something went wrong with the original project.  I've tried to edit the original project to more closely match the new one and it still dies.  Guess it's time to put it to bed.