The first issue is an alacarte bug (Bug #1069207). I still can't reproduce your issue though, even if I install arduino (it shows up in Development), then open alacarte, still no Electronics submenu appears in the panel menu.
** Tags added: unreproducible -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1026058 Title: Applications Menu .desktop item with category Electronics creates an uneditable sub-menu Electronics To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xfce4-panel/+bug/1026058/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
