I have a problem with your plugin, I was using phplist alone but recently Iam using zingiri plugin of phplist for wordpress.
The problem that when Iam trying to search a user, no any results appear just a blank page .
this is the link after i press on find button:
and just a blank page, and this problem appears in firefox, chrome and IE.
I tries the plugin on another wordpress site and the same problem is occurring.