Conflict with both WordP and WP User Frontend Pro

There seems to be a conflict with both WordPress Creation Kit Pro and WP User Frontend Pro and this plugin.

To clarify:

1. I’m not using both (WCK and WP Frontend) at the same time as Find Your Nearest. I’ve tried using one or the other and both fail to post from the front end of the site when this plugin is enabled.
2. I’ve disabled all my plugins except for either of the two and Find Your Nearest.
3. Same on different themes and an older version of WordPress.

I need either one of these plugins to work for my site. I’m really at a loss on how to properly troubleshoot a conflict like this. Any ideas on how to do some basic diagnostics on the site so I can get an idea on what the issue might be?

Thanks in advance.

http://wordpress.org/plugins/wp-find-your-nearest/