infected with Win32: Dropper Gen [Drp]???

Hi, I have tried to download Messenger Plus for Skype and my Avast Internet Security detect it as a malware (Win32: Dropper Gen [Drp]) the matter is i have been using it for long time along Avast on Win Vista and I never got a warning from Avast before.
Now after Upgrade my SO to Win7 and try to instal it again It is detected as a Threat. Is it a False positive?
Anyone can give me any advice about it?
Besides this matter a moment ago i called to your “support” center and looks like the girl which took the phone call don’t know anything about it, she was just babbling answers without any sense
and she couldn’t provide any useful info. Instead of, she advice me come to forums to get some help??? (second time I got poor support from you guys, you have to take care about it.)

Hi,

You should provide us with screenshot that can tell the full file path of detection. Know that ‘droper.gen’ means just a generic detection.

You may use this form for contacting someone from avast! team.
http://www.avast.com/contact-form.php

There is not any path, avast warning comes just click in download button, and avast blocks page and send file to Virus box, so nothing to download nothing instaled.

from where do you download?