Hi Shields,
I apologize for the slow reply, this message slipped through the cracks... You probably already solved it, but here is an answer.
Edit the transaction that caused this position in the Data Register. Select "Investments (all)" for the data type, select your transaction, and press "Edit...".
Yes, you can "hide" sold positions, and turn off the option to retrieve prices. You can either do this manually, or with the "File / File Operations / Hide Sold Investments" command. See:
http://www.fundmanagersoftware.com/faq_hide_sold.php