I think I did change it years ago in CR7, but since then I have switched to using stored procedures, which is way more flexible than setting up the table joins in Crystal.
If you can, I recommend using the stored procedure approach as it gets you around things like this...though you will have to find the stored procedure, which might still be an issue if Crystal is not reporting all the tables.
It's odd that Crystal doesn't report all of your tables, we have over 800 tables and don't have any issues that I am aware of, and we have much more than that in the stored proc list.