2011/7/16 Andre Engels
<andreengels@gmail.com>
It happens that category.py (and in general bots that work on categories) work by getting a list of the categories and interwikis, then adding or removing on the list of categories, and then re-creating the page by putting the part that is not category or interwiki on top, then the categories, then the interwikis.
The interesting thing is that category.py did not produce this behaviour earlier (this is not the first time I wanted to use it for deleting a category).