It has often happened with me that what I considered was a problem was only a symptom of the real one. For the user, the symptom is usually the problem itself. That is why it is all the more important for a problem solver to sift through the symptoms and arrive at the underlying problem. One of the differences between the symptom and a problem is that the symptom will usually be more about the environmental factors and external systems. This includes those problems that occur intermittently are not easily reproducible. Instead of giving up on them, acknowledging a deeper problem and investigating a wider area might lead us to the real problem.