(Edit your project's description!)
This is my first attempt for building an elgg plugin. It just lists all the elgg users in a site, so that you can navigate the full list of members (it is the same than in the administration panel, but now for all the users).
I'm running Release - 1.2, Version - 2008120901of elgg. I added the uncompressed folder to my <root>/mod folder. I activated the plugin. All my pages now show php code in the pages and widget headers. Deactivating the plugin all was well.
Some possible problem with the newer version? It seems to have been working before.
.. By the way, you sould also consider changing your language strings to start with your plug-in name, as documented in the best practices: http://docs.elgg.org/wiki/Engine/Internationalisation#Adding_language_files_to_plugins_.28and_best_practices.29
For example, instead of "memberlist" use "everybody:memberlist".