Which distributon are you using?
Debian was updated to 5.0.6 but those file listed there have not been updated. It looks like some have been modified.
You can try to update rkhunter database:
Than do another scan, if rkhunter shows same error than i would advised you to take down the server and inspected without it been connected to network.
The best solution is to reinstall the server an re import backup. Because you never know tha intruder have done to system.