Having the same issue here, networked configuration, with FSX, Windows 7.  Drop down opens and allows entry of locations but there is no confirmation button, no ok button in the lower right corner of the drop down, program crashes before or when the drop down is closed. and the locations are not saved.  Event viewer shows corresponding .NET Framework error.  Tried both routes to build.

Thanx

Never mind fixed it, danged Windows Firewall, FIREWALL THIS MICROSOFT!!

Cheers!