The details with screen shot and source code are described here: http://stackoverflow.com/questions/7892521/saving-a-pdf-using-aspose-net-constantly-grows-in-file-size-how-do-i-prevent
Thank you very much for considering Aspose.
I have replied in the mentioned thread on StackOverflow.com: http://stackoverflow.com/questions/7892521/saving-a-pdf-using-aspose-net-constantly-grows-in-file-size-how-do-i-prevent/7893649#7893649.
The reason of this issue is the evaluation mode. I have also shared how you can fix this using a temporary license while you’re still evaluating the component.
I hope this helps.