Rails-3.0.3 API change? Completed 406 Not Acceptable

X-posted from Ruby-on_rails Talk

Updating to Rails-3.0.3 resulted in 14 tests failing. Investigating one of them I discover that this message "Completed 406 Not Acceptable in 223ms" is being returned instead of the expected page. This error indicates that the format of the request cannot be satisfied. Usually a format specification is html or json or pdf. Imagine my surprise then when I see in the html generated from the view template:

<td> <a href="/user/roles.1" id="show_user_roles_administrator_link">Roles</a> </td>

instead of:

<td> <a href="/users/1/roles" id="show_user_roles_administrator_link">Roles</a> </td>

The question is: Why is Rails 3.0.3 asking for a format of .1 instead of requesting a user with id == 1? Is this a bug or an API change?