If your adding the tables with same name from different database then crystal report  will create an alias for that table. i mean if you already have table name "emp" and if u add one more table with name "emp" then CR will give a database warning "The table "emp" has already been added to this report. Do you really want to add another alias to this table"?. if say yes then table is added with name "emp_1". so you will get your table but the name will differ slightly. 

so check this and get back if u have any queries