To resolve this you're probably going to have to track down which version of what caused things to break and then raise a specific bug report against the specific component. And that will likely be a PITA, as there are so many versions and combinations of versions to test. For example; threads appears to have gone through around 20+ version between where you are and I am.

A few things that might help:

• I downloaded the latest version (v109) of Event that was available from CPAN. I'm not sure how/where you obtained a later version?

  It's also worth poiting out that the POD carries the following warnings:

  The scope of events is pretty strange compared to most other perl objects. I'm not sure if this is a bug or a feature (OK, probably it was a mistake). ...

  There seems to be some sort of bug in the global destruction phase:

    Attempt to free unreferenced scalar during global destruction.
    Use of uninitialized value during global destruction.
    Explicit blessing to '' (assuming package main) during global
    destruction.
  [download]

  The latter may be, (is probably), the source of the "1 leaked scalar" message issued. Although this message is associated with threads, it may well be that it is simply that it bothers to check.

  Ie. The scalar could be leaked whenever you use Event, but is only detected and reported when you use Event in conjunction with threads.

  The former may mean that the two modules may never properly coexist?

• You might be able to verify the source of the problem as being in the eevent module, by using them together within the same program, but but keeping their respective code separate.

  Ie. Start and join a thread from the main thread, but do not use Event within that thread. Then create an Event timer callback, that does nothing with threads; run the dispatch loop and allow the program to terminate. If you still see one or the other of the symptoms, it will indicate...something :)

• I've downloaded, but haven't yet installed the latest CPAN version of threads.

  I'm a litte reluctant to risk screwing my main installation of Perl, but I may try backing up my libraries for quick reversion, and installing it later tonight.

HTH some. Good luck.