RCM400 - What does this error "Bad parameter passed to I/O function" mean?

Hi, I need some help!!!
I’m using a development kit of the RCM4000, and I’m new to Rabbit hardware.
First I was trying to use a sample programs of the “analog ports” (A/D Converter Inputs), but none works, every time appeared this error: “Bad parameter passed to I/O function”.
I don’t know what this error means exactly. :confused:
If someone knows this, I appreciated any help.

Sorry for my English. I’m from Brazil and I’m not fluent in English.