gitk "reset branch to here" bug in Cygwin

Greetings,

First create a test repository with two commits:

mkdir gittest3
cd gittest3
git init
echo foo > foo
git add foo
git commit -m "Foo"
echo foo >> foo
git add foo
git commit -m "2nd. foo"

Now start gitk, point at the first commit and from the context menu
select "Reset master branch to here" and then "Hard:...".

The result is 'can not find channel named "1"'.

git reset --hard HEAD\^1 in the same repository works fine.

Tested with 159c88e5ae95c5b02298193c1658fac5919c8012 (1.6.1 plus a
few commits) on Windows XP.

-- 
Hannu