There are a lot of versions of this app floating around. Some had some serious issues with filling up the notification queue. Install Memmaid and use the notification queue tool to check for duplicates and delete any found.
I don't know if your phone runs WM5 OR WM6, but here is the version of the HTC Home Plug I would suggest. It is designed for WM6, but if you read through the thread it also explains how to use it with WM5 if that's what you need.
http://www.ppcgeeks.com/htc-home-plu...ort-t7086.html