Since I'm in the mood for posting, let me see if I can help you with this one too. When you set up a counter it creates a ouput task on the PFI line. However, when you set up a task to use this same PFI it is trying to use this as an input. I don't believe NI-DAQmx Base supports this. You should try wiring the PFI line to a different terminal to input to the card. Obviously this is not ideal, and I am sure that the error doesn't make sense. I'll set up something similar in a bit if I get a chance and see if I can reproduce the error.
Whether we get this working or not, as I mentioned in my other post, it may make sense to explore using NI-DAQmx rather than NI-DAQmx Base. I'll let that discussion continue in your other thread: