Crystal Report Dataset table dependency null issue.

I am working with one maintenance project. I have to modify one existing rpt file. I work with VS 2005. It is a xsd based rpt file. We have 5 tables in the dataset. Out of this, 2 tables will always have values. Other 3 tables can be null also. My issue is ,when I access one table in crystal report ,it returns proper values only when one of the optional table has any rows in it. If optional table is null, this table returns null even if it has values (the values which I am setting from code.). Has anyone faced similar issue? How to solve this? How to remove this dependency? Please help me out.