Ahmad,

There are a couple of reasons why this can happen. Here's the one I've seen...

When you designed the report, I'm sure you specified a data source for the data in the subreport. If you're using setdatasource at runtime to set the actual datatable(s), you need to do that for the subreport as well as the main report. If you don't, I think the crystal runtime goes 'looking' for the data, and that might explain the login prompt.

Hope that helps...
Kevin