This is a bug and a small new feature enhancement.
Bug: When you specify the
parameter, sort no longer works.
New feature: When
you can specify the number of header rows to exclude from sorting using the
parameter (existing feature). The new feature makes the
parameter optional. In case not specified, it takes all header rows into account.
This new feature brings a small change in behavior: Previously the last header row was converted into sort links, now it is always the first table row. If there is a need we can add a new parameter to specify the old behavior.
This is now in SVN trunk and 5.1 branch. Docs are updated as well.