Demo limitations

I am evaluating Aspose.PDF and sometimes it only extracts the first line and other times it is only extracts part of the first line.  

Is this a limitation of the demo version?  How can I test this product before purchasing it to prove it can handle our varied and very large documents.

The reason I ask is that just last week I purchased another product that worked fine in test on a 32- bit machine but failed to work on the 64-bit servers.  I cannot afford to recommend another dud to my client.

Thanks.

Here is the code.  Debug shows that the memoryStream is huge but the extractedText is tiny.

                            Document pdfDocument = new Document(memoryStream);
                            TextAbsorber textAbsorber = new TextAbsorber();
                            pdfDocument.Pages.Accept(textAbsorber);
                            string extractedText = textAbsorber.Text;