Searching the code I find a number of scripts with this line:
Code:
@ini_set('memory_limit', 128 * 1024 * 1024);
which changes that value, and 128 * 1024 * 1024 = 134217728. But I don't know why it would remain at that setting after the script ends, or why it would report different values between your two sites. Maybe it has something to do with web server threads or something.