I'm trying to change the shortcut for switching applications from Alt+Tab to Ctrl+Tab, but changes in the System Settings > Keyboard > Shortcuts > Navigation are being ignored. Even if I disable the Switch applications shortcut entirely, it still maps to Alt+Tab. At one point I had some keys remapped with xmodmap, but since then I have deleted that configuration and rebooted. My keyboard layout settings are all defaults. The OS is Ubuntu 12.04, with all software updated this afternoon.

It would also be nice to have the variation of application switching that includes one icon per window, instead of one icon per application, since I am frequently switching between windows of an application and would rather not wait for the switcher to realize I want a different window of the current application. My other Ubuntu 12.04 install has the application switcher that I like, but I'm not sure how to choose between them on this install (which was set up by my university department). Thanks if anyone can help me with this.