I think we both might be right on this question. There is one issue of lvalue calculation in a single statement. Then there is the issue of what happens in a sub call with say foo (++I, --I). In C, we don't know whether "I" will get incremented or decremented first. This is like when you go to the doctor and you say, "it hurts when I press here", and he says, "don't do that".
The fact that we are "arguing" about some syntax says to me that the syntax isn't clear enough. I am not gonna argue precedence.. Hey, that there is even a question at this level means it the code was not clear enough to begin with!
Think about what will happen say 2 years from now? My opinion is that clear code is good code.