I have configured a 10.10.1.0 255.255.255.0 as a private address for NAT translation on the PIX515 which running ios version (5.1.2).
Every so often I can not access servers on the LAN as well as outbound connections to the internet stops working. I use the clear xlate command to fix the problem.
I have defined a global ip range of 4 public addresses and a PAT address.
Recently I have changed the xlate timeout from 3 hrors to 3 minutes.