Prompt Page Not Displaying in Cognos Viewer After Migrating from 8.3 to 10.2

[Sprinter29]

The company has recently upgraded from 8.3 to 10.2. I developed a portal page that contained few reports that i developed. One of the report has a prompt page containing value and search prompts. The same portal was running fine in 8.3 but after migrating the report with prompt page is not displaying the prompt page in Cognos viewer window of the portal page. The same works fine outside of the portal or if I run it in a separate window in the portal, but it times out in cognos viewer window.  Any suggestions/help please?