File Download Dialog Box would not popup after report generation

I'm encountering a weird error with Siebel - BIP integration.  When generating report from Siebel, the file download dialog box don't popup.  In the task manager, you can see a task named "Asychronous Server Request" which I suppose is the popup applet which I can't access even if I try to do a "switch to" option.  When I end the Siebel task, and relaunch the application, I see the report successfully generated in the "MY BIP Reports" view and I can access and download it from the file system.  This tells me that everything is successful except for returning it to the user to download