Please check in following sample config:
http://www.cisco.com/warp/customer/110/pix3000.html
Please check the access-list 101 and "nat inside 0 access-list 101"
This is the way how PIX bypass the NAT.
By the way, are you client PC has a public ip address ?
If your client PC is behind a PAT equipment, you can connect , but you can not pass any traffic.
Becaue "IPSEC over PAT " is not supported on the PIX yet.
Best Regards,