Dimension options (cohorts) are not sorted when setting up a dimension. For example, an age dimension ends up sorted in this order...
Ideally they would be sorted alphabetically, or saved in the order that they are entered.
This happens in my implementation and on the demo server, both running Reporting 0.9.2.1.
When using the dimension in a cohort indicator report, the strange order is also presented there which makes it likely for items to be added out of order or missed.