I have messed around with this alot now and haven't made any progress appart from learning something about the invoke nodes. I think I will have to agree with you.
I went ahead and pulled previous versions of the dll going back 4 years and every one of them has the same parameter list. Perhaps more suprising (or not as you reply indicates) is that they all have exactly the same version of documentation with them (Ver 1.0).
Looks like it is time for a rethink.
Thankyou for your help.
David