Plugin is available to update when its not

I have developed a plugin for my client, but for some reason, its saying that update is available.Whereas i have no idea how to feed a update. The plugin says in update field, about author with a different name (not me), its a totally confused situation. If someone hit update, my plugin can be overwritten by someone else.
Why is it happening?
How i make sure it is not updated by any other means, only if i have feed it to update.

WordPress’ update checker is known to be quite greedy. To prevent these notices:

• use a unique name for your plugin
• use a unique directory name
• filter http_request_args and prevent your plugin from being checked (example)