Rails-3.0.3 gives Completed 406 Not Acceptable

Rails
1

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 tha 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:

Roles

instead of:

Roles

The question is: Why is Rails 3.0.3 asking for a format of .1 instead of
requesting a user with id == 1?