We have the portal 7.3 SP09. It also has an external link.
The Bex Reports are running fine and populating data correctly. But when the "Export to Microsoft Excel" functionality is being used it is behaving differently.
When done via the internal link - The export functionality is working as desired. A new windows pops up, and then closes. Then a prompt appears to save the generated excel.
When done via the external link - A new window pops up and then closes. That's it. The next prompt does not appear.
All the checks of pop - up blocker is disabled.