RE: Diff bug when using the HEAD tag?

[Deever, Chris C.]

>When you're working on a branch, "HEAD" means the head of the branch,
>not the head of the trunk, at least for diff.

>-Larry Jones

Please forgive me if I'm not yet on the same page, but I can't seem to fit
that explanation into my scenario.  

The diff from the branch to HEAD *did* report some of the changes, except
for two changes that happened to be in a file which there are in two
different copies of the same file located in different parts of the project
(a shared data structure between client and server).

                    new branch
                        |
base line version -> rel tag -> a little more development -> current

The above shows the tree.  When I am in "current" and diff against "new
branch" I see all of the changes that I expect.  However, when I am in, "new
branch" and I diff it against HEAD (which I am expecting it to be the latest
changes comitted in the repository), I see only part of the changes.

Either there is a bug or I'm not understanding something.  Branches do not
automatically get changes from the trunk, do they?

Regards,

Chris