How to solve inconsistent NI USB-6009 behavior

I have a NI USB-6009 DAQ connected to a Windows 32bit machine. MATLAB's recognition of the device is very inconsistent. I am connecting using the session interface from the Data Acquisition Toolbox. About 50% of the time the session cannot be started, and I get the following error

The vendor 'ni' is not known. Use
'daq.getVendors()' for a list of
vendors.

I follow this with

daq.getVendors()
ans =
Data acquisition vendor 'National Instruments':

            ID: 'ni'
      FullName: 'National Instruments'
AdaptorVersion: '3.8 (R2015b)'
 DriverVersion: '15.1.1 NI-DAQmx'
 IsOperational: true

It seems the vendor should be recognized. However, when this happens I can also get the following result

daq.getDevices
ans =
No data acquisition devices available.
Click here for a list of known vendors.
Click here for troubleshooting tips.

I am looking for suggestions on how to fix this problem. I have seen similar issues posted numerous times on MATLAB Answers but the suggestion if always to install the 'NI-DAQmx' support package. I have already done this, and I am unsure what else to change. Thank you for any assistance.

Extra Details

OS: Windows 7 32bit

MATLAB: 2015b

DAQ Toolbox: Installed

'NI-DAQmx' support package: Installed

DriverVersion: '15.1.1 NI-DAQmx'

RAM: 4GB CPI: 2 Dual Processors Intel Xeon E5502 1.87 GHz each

Other Running Packages: Image Acquisition Toolbox, Image Processing Toolbox

Device Functioning: The device always works in provided NI testing applications. It establishes a connection in about 50% of cases in MATLAB

Reconnecting: To fix the issue I have to close matlab reconnect the USB-6009 then reopen MATLAB

Answer 1

[Michael McConnell]

I may have found the solution to the problem. It seems that the DAQ is always able to connect when the NI Device Monitor is not running in the background. I haven't tested it rigorously, but after exiting the monitor from the windows task bar, the issue has not reappeared. I am going to mark this solution as the answer, but if anyone has other suggestions feel free to leave a comment.