Comment 4 for bug 608746

"^Start Kubuntu" label is localized and translated into Spanish since 2010-08-24:

  https://translations.launchpad.net/ubuntu/maverick/+source/gfxboot-theme-ubuntu/+pots/bootloader/es/45/+translate

However, the menu item still shows untranslated in 10.10 when the user selects other language than English.

I've submitted bug #666716 to track this issue.