Parameter used multiple times with conflicting datatypes

[Gary]

Hi

I have 2 cognos queries Q1 and Q2. In Q1 i am using Oracle SQL to fetch data where i am fetching some date column. I can have null values in this filed for some rows. For the null values, i am parsing some default value to 10 years back in another data item using add_years (current_date,-10),

In Q2 i have records from different query subject with one data item as some date

to filter records based on date, i am using date prompt where i am condition Date from Q1/2 < pmtDate.
If i try to see data of these queries independently, i am able to view, but when i execute the final report query i am getting error " pmtDate used multiple times with conflicting datatypes"

Any help on this?