Syslog is seperate than PDM. PDM is used just to manage the PIX and does not serve as a Syslog. You have to implement a seperate Syslog server. You can also try using PIX Firewall Syslog Server (PFSS).
http://www.cisco.com/univercd/cc/td/doc/product/iaabu/pix/pix_v52/install/pfss.htm
There is no PDM documentation on CCO currently but plans are undeway.
If you have a problem or need assistance with using the PDM, you can open a TAC case and they will assist you.
HTH
R/Yusuf