It's definitely not a common problem. Something must be interfering with it. I think you first need to establish if it's a connection issue. There are no compatibility issues with Windows 7, it is developed on a Windows 7 PC.
1. Check your proxy settings, it may have changed without your knowledge. See
http://support.microsoft.com/kb/135982 (it uses the same settings as Internet Explorer)
2. Reboot your PC and router.