Binary file appended instead of created

I have two machines for data acquisition. The first computer (labview 8, 2.8GHz, 1GB ram) contains a pci-6133 and pci 6052e. I am using the 6133 card to acquire 8 analog inputs at 50kHz  and the 6052E to generate a trigger pulse.  On the second computer (labview 8, 2GHz 512MB ram) I have a pci-6602 that I am using to acquire two channels for buffered event counting.  I  export the sample clock from the second computer to the first and have them both started on the same trigger.  Since I need the files on both computers to be referenced to each other, I generate a timestamp and convert it to a string. Then, using the shared variable engine I share the string between both computers for use in generating filenames. For example, I concatenate "Tracking_","<timestamp>",".dat" on the first computer and "Spectrum_", "<timestamp>", ".dat" on the second computer. Whenever I stop and start the data acqusition I want a new file created on each computer with the correct filename.
I set the open/create/replace vi to "create only" on both computers.  When both computers are running, computer two successfully creates a new file with the correct filename and saves the data until the acquisition is stopped. However, with both computers running, computer one only creates a file once after I initially start the vi. When I stop the data acquisition and restart it (without stopping the vi), computer one appends the new data to the previous file and no more new files are created.
When only computer one is running (and I generate the sample clock from a spare counter) , the code works correctly.  A new file is created when the data acquisition is stopped and started.
From the symptoms, it would seem to be a problem with the use of the shared variable engine but I am not sure how. Any help on this problem would be appreciated.

Without a look at your code, I am correct in understanding that the filestamp from the shared variable will 'name' the file?
In that case make sure you get a 'new' timestamp.
Ton
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