Try deleting your winfilecache.dat file in your user's configuration folder. If you post a US phone number or Skype contact information I can call you tomorrow to work through your issues and get the extension installed properly.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.