conflict between plugin and w3cache

Hi, I’ve a problem with this plugin and w3 total cache. When I use the login first time after caching browser it works, but when I use dashboard or any others page in the site, the plugin doesn’t work. I tried to empty cache in w3 but nothing happens. I tried to deactivate manually plugins but it’s the same. To make plugin working the way is deleting cache on firefox, ie and safari. It seems that on caching the plugin doesn’t work.

Any idea?

Thanks

https://ww.wp.xz.cn/plugins/sidebar-login/