Comment 4 for bug 301767

The package appears greyed out because it lacks some dependencies. apt-get will show you which packages need to be upgraded or to be removed with netatalk.
Depending on the output you can choose to upgrade or not. If apt-get doesn't show anything special then update-manager should show the package as upgradeable.
I hope this helps. If in doubt then provide the output of apt-get before answering yes to the upgrade.