Redo-shortcut vanished - eclipse on OSX

Question

For quite a while my Eclipse Juno won't let my redo my undo's via shortcuts, although the binding is set properly and I didn't change a thing. You can see there's something wrong here as the shortcut isn't even listed anymore.
That's how it's set in the settings:

Did anybody encounter the same problem? I have the problem at 32 and 64bit Eclipse Juno Service Release 2, Build 20130225-0426 on OSX 10.8.3, but I think it was already there back with 10.8.2.

Answer 1

If you describe your redo key configurations like below, your problem will be solved.

Answer 2

vtokmak's answer seems to be working for most, but it's probably worth noting that for some other users, the problem may be conflicting key bindings. You can check/rule this out by searching for the binding your shortcut ought to be (e.g. "Shift+Ctrl+Z". Be careful of order).