Drill through producing empty results

[fml55555]

Hi Gurus,

I have created drill throughs from report S to T. Report T has many optional filters to accommodate which column of report S is clicked by the user. I am facing the following problem

Report T shows "No Data" when I click on a column in report S with Show parameter box as :"Only when required parameters are missing" OR "Based on default prompt properties of the target report".

However, when I use "Always" and I see the parameters being passed and have to click on OK to complete the drill through, I see the data in report T. Why is this happening?  I think that the values are being passed but the report is somehow not 'submitted' with the values.

Environment: Cognos 10.2.1
Model: DMR

Thank you!