Random deactivations

Ever since getting this plugin I have been battling with keeping it in “activated” mode. Every week or so I find out that the plugin is deactivated because my users complain they cannot access the WP site while they are logged into PHPBB. Sure enough, when I go to the WP Admin panel, “wp-phpbb-bridge is not activated yet…”.

Here’s what I’ve checked so far

1. Checked apache logs for someone hitting the deactivation link.
2. Changed deactivation string and repeated above.
3. Altered wp-phpbb-bridge code so the deactivation page runs die() on line 1 to cover against brute attacks on deactivation.
4. I have 1 other admin on the system who says he has never touched the plugin settings. Just to be sure, /inc/admin_pages/settings.php runs die() on line 1. The plugin still gets deactivated.
5. No one has database access to change activation status manually.

I am lost! What could possibly be deactivating this plugin?

Any help appreciated, thanks!

http://ww.wp.xz.cn/extend/plugins/wp-phpbb-bridge/