Two different email addresses would not make any difference. I don't have access to Vista but from
what I've read online, the problem appears to be with your Hosts file in Vista. You will need to edit
this file and that should fix the issue.

Here are the directions:

1) Browse to Start -> All Programs -> Accessories
2) Right click "Notepad" and select "Run as administrator"
3) Click "Continue" on the UAC prompt
4) Click File -> Open
5) Browse to "C:\Windows\System32\Drivers\etc"
6) Change the file filter drop down box from "Text Documents (*.txt)" to "All Files (*.*)"
7) Select "hosts" and click "Open"
8) Make the needed changes and close Notepad. Save when prompted.

I will also have Sales send you an invoice.