While this version is known to exist, it is missing from the launcher and has not been archived elsewhere, meaning that it is currently lost.
If you believe you have a copy of this version, please post on the talk page.
A version of Indev 0.31 was released on December 31, 2009.[1]
Note that the Creative mode inventory was still in the code right up to Beta 1.7. (Creative mode was re-added in Beta 1.8 Pre-release, 618 days later).