A quick search of the forum turns up a thread with this link:
Porsche Resetting Radio Codes
I used it too look up a code for mine a month or two ago and it worked well. I don't know the origin of the site and I had to change and disable some of my my Java security settings to use it. If I get my old 'non-secure' notebook out I may look it up for you.
Update: I just entered your serial number in that web page and came up with "9502" as the first choice code. 2nd choice is 9512, 3rd is 9602. The site says that the first choice should work almost every time.