I would use Profiler to see what Crystal is passing to the database and then running it in Query Manager.

If you have additional filters in CR that are applied after the initial query to the database (record selection formula), it might be that there is alot of data.

Perhaps you can use a stored procedure and pass all of the parameters to the database and let it do the work, so that all CR has to do is manipulate the display...which it is good at doing.

HTH