I moved a configuration from an ASA 5510 to a 5512, and in the process, went from version 8.4 to 9.0 of the IOS software. When we hook the firewall up, I can get to it from SSH, or from the outside, but a number of the NATS don't appear to be up, VPN connections via the client don't work, and there is a L2L VPN Tunnel that isn't working either.
The only differences between the configs are the RSA key, which I had to regenerate for the new firewall, and I had to manually install the cert. I can't imagine where either of those would affect IP NATs though.
Curiously, all of the NATs that aren't working appear to be on a separate external subnet than the ones that are working, but those networks aren't defined in either config.