The API supports two methods for continuing action=query when more results are available, the simple method and the raw method. The raw method is currently the default for historical reasons, but as the simple method is much easier for new users to use *correctly* that really should be the default.
To make this transition easy for clients, the current plan is to make the change on the following timetable:
* Starting with 1.24wmf22, action=query will recognize a "rawcontinue" boolean input parameter. Clients that wish to continue using the raw method for continuation should begin supplying this parameter with all action=query queries.