Thank you, Garciaj, for your post. It seems that a few minutes after your replied to this thread, some people at Watlow have replied to yours with the solution.
For those that are reading this post for the solution; the problem, for me, was having the controller set in Degrees Celsius mode. Apparently this is a known issue with the LabView driver, and you should only issue write commands in Fahrenheit mode. A very strange bug, given that I am not modifying a temperature set-point or anything.. but I am glad to be told the solution and to have code that works.