strange, but in debian i have the following /etc/hosts :
Luca Bruno [ Editor ]
This is a tricky question :)
Short answer: both are correct, the difference is that debian installation was done with an already configured 192.168.1.0/24 address, while the ubuntu one not, thus it is using a loopback address (the entire 127.0.0.0/8 is assigned to loopback, so 127.0.0.1 and 127.0.1.1 are almost equivalent).
Long answer: local machine naming is a tricky matter, which may impact on applications in a wide variety of ways, in particular for roaming machines. The scheme for /etc/hosts naming and the pattern you are seeing are a result of some discussions, which can be read through the log of bug #247734.