Well, I think that the operator precedence rule is there for at least two reasons, above and beyond programmer error: (Perhaps that should be reworded to "I recommend the operator precedence rule because...")

1) Precedence tables are not consistant across all languages
2) Precedence tables are subject to change in non-standardized languages.

While there has been an obvious effort to keep the main operators (arithmetic, in particular) consistant and based off of the mathematic precedence table across most languages, when it gets down to things like bitwise ops there is a lot of room for difference. I can't think of an example right offhand, though.

~Cybercosis

nemo accipere quod non merere