Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it.
-- Brian W. Kernighan
The PPL developers encourage you to report any bugs you find using the bug tracking system. Here `bug' should be interpreted in its broadest sense: outright software errors, misfeatures, bad interfaces, missing or unclear documentation... whatever is a subject for possible improvement.
As far as software bugs are concerned, the best reports are those that are reproducible. When possible, including (or pointing us to) code that exhibits the reported misbehavior is the best thing you can do to help us fix the library. Of course, this is not always possible and we will welcome any kind of bug report. Anyway, you may be interested to read How to Report Bugs Effectively, by Simon Tatham.