Third newbie question: gitk --all refresh?

I have a little problem: is gitk supposed to be possibly run in background and then refresh when told? It seems to me that it can track only some changes... Better let git (1.0.8) speak:

pern:~/% mkdir gitk_r
pern:~/% cd gitk_r
pern:~/gitk_r% git init-db
defaulting to local storage area
pern:~/gitk_r% echo "one" > one.txt
pern:~/gitk_r% echo "two" > two.txt
pern:~/gitk_r% git add .
pern:~/gitk_r% git commit -a -m "commit 1"
Committing initial tree efa4c546776cd5539cb54969a5e1c110b3232ee2
pern:~/gitk_r% git branch
* master
pern:~/gitk_r% git checkout -b second master
pern:~/gitk_r% git branch
  master
* second
pern:~/gitk_r% echo "three" > three.txt
pern:~/gitk_r% git add three.txt
pern:~/gitk_r% ls
one.txt  three.txt  two.txt
pern:~/gitk_r% git commit -a -m "commit second"
pern:~/gitk_r% echo "one one" >> one.txt
pern:~/gitk_r% git commit -a -m "commit on second #2"
pern:~/gitk_r% git checkout master
pern:~/gitk_r% echo "two two" >> two.txt
pern:~/gitk_r% gitk --all &
[1] 787
pern:~/gitk_r% : Now git is showing ok
pern:~/gitk_r% git pull . second
Trying really trivial in-index merge...
Wonderful.
In-index merge
 one.txt   |    1 +
 three.txt |    1 +
 2 files changed, 2 insertions(+), 0 deletions(-)
 create mode 100644 three.txt
pern:~/gitk_r% : Now gitk refreshes ok

What I mean if that I select update - reread references it's all ok, I see the merge.

pern:~/gitk_r% git branch -d second Deleted branch second. pern:~/gitk_r% : Now gitk did not delete the second branch

What I mean that I can do the same update - reread references but "second" branch stay there...

pern:~/gitk_r% : but pern:~/gitk_r% gitk --all pern:~/gitk_r% : this is ok

That is, the two instances of gitk --all are showing different things: the "old" running one continue to show the old "second" branch in green.

Is this supposed to be like that? Or is "driver" (aka /me) error?

   Romano