Thanks David. In response to your post, I re-read one of those old threads (http://www.empirisoft.com/Support/showthread.php?t=511) and modified my last post to read:

Try running the simplified "sampleinput2.csv" input file above. If it works fine but yours does not, then can you tell me if you are using a grid based system (e.g., cursor, touch screen, light gun) at all in your session and what version you are running, i.e., 200x.x.x?
Just curious to know if it is limited to cases where grid systems are used in the experiment.