That depends on your version of Crystal,the database used, join types, and other technical issues. If you have a dba, consult them. Crystal is a relatively easy product to use, and hence gives the illusion to many that they don't need to understand data, but this is not the case.
Otherwise you might use a subreport for the Master(acct)->Orders portion.
If there are multiple orders, how would you determine which of them you want to display?
perhaps you mean that you're getting the same order numerous times?
A short text description isn't very useful, please provide technical information if the above doesn't help:
Crystal version
Database/connectivity used
Example data
Expected output
-k