BO Dashboards 4.0 - Query Prompt Issue

Hi Guys

Please help me in resolving the following issue..

Tool  : SAP BO 4.0 Dashboards Patch 12

Issue : Query Prompt issue in Dashboards

Prompt in Query Browser :Not local prompt created in Query browser , it is from BW query

Getting no values to dashboard if Query prompt is mapped with Combo box (which throws empty in) destination cell.

Cell A1 (Contains no formula) - Empty  (This cell is Combo box Destination throwing empty value)

Cell B1 (Contains no formula) - Empty

Mapping to cell A1 is not working but with cell B1 is working.. Tried with ="","" in cell A1 but no luck.

Also tried with Div/0 error which is identified as empty cell , as somebody suggested but no luck.

Any solution would be highly appreciated. I cant use query prompt selector component because it is mobile dashboard.

Thank you.

Sivaji