Fixed in r4437.

Just replace line 49  
    istream &in = cin; 
with
    ifstream in("output");

As long as it isn't too tough, I'd rather keep support for the old format around
because it allows us to make regression tests against the old translator code.
I'll try to fix peek_magic; shouldn't be too hard.

Do you have some code I can use to reproduce the problem?

This is because of the peek_magic function, which for some reason does not work 
for ifstream objects.
I think we can get rid of this with the "official release", since it was only 
meant for backward compatibility with old versions of the translator.