Hi Dmacintosh,
Once you void Quotes in Sales Order Processing, they move from the Work table (SOP10100) to the History table (SOP30200). This is the main reason why you will not be able to pullup voided documents in the Sales Transaction Entry window since it only looks at WORK transactions.
The only way to view them is to use the Sales Transaction Enquiry Zoom window via the Sales Order Processing Document Enquiry window (Enquiry | Sales | Sales Documents).
Let me know if you have further questions.