As far as I know, the only official release of the 9.X line of the tool was version 9.2
Do you have version 9.1? If you do, the only way I can see that having come into the company was if they participated in early testing. Usually the .0 and .1 versions are preview and the .2 is the actual release.
The difference would be more in the bugs that were fixed than the addition of features IF that is the case of you actually having a 9.1 version