Something is very, very wrong.

Code:
#include <iostream>

int main() {return 0;}
Gives exactly the same errors.

It does the same with fstream, so I'm guessing there's a really messed up header related to streams.

BTW, I'm using the standard GCC compiler from the Kubuntu repositories. It's version 4.5.

I'm going to reinstall the packages and see if it helps.