I am not having any trouble with the Nutrition Tracker, and we have not seen other complaints like this. If you are still having trouble, you might want to clear your browser's cache and cookies to see if that helps. If you need help with how to do that, you can check out this Google page for instructions: support.google.com/accounts/bin/answer.py?
If that does not help. Let me know exactly what is happening when you try to track your food.