Whenever XML::Simple isn't doing exactly what you want, it's time to use something better. It's designed to work with smallish hashes, not solve all of your XML needs. Besides that, you'll have to tell us a lot more about your situation before we can even guess at the problem.
When you run into a problem, try to reproduce it in a small test case. That might be as simple as a program to read the file and access it. Remember, you're the primary person responsible for solving your problems. :)