Matt - sorry, this post fell through the cracks.
You are most likely receiving that message because you passed an empty field name.
My guess is that you split a comma separated string into an array, and the last field still had a "," after it.
For example:
field1,field2,field3,".Split(",")
would actually create an array of 4 values, the last being empty.
So instead if you made it:
field1,field2,field3".Split(",")
There would only be 3 in the array.
That's my guess anyway, since I have had this happen before, and it is always a typo I've made.
Side note - sure am glad we turned these techie topics into a separate forum! :)
HTH,
Paul