Live USB faster than full install

When I run 11.04 from a USB flash drive, it works the way I suspect it should - quick and responsive. With a full install, on the other hand, I click the home button and I have to wait four seconds to see the dash (this is insane - I have a core i5). Same thing with alt+F2.

I've also tested the live USB on an older laptop with inferior specs and it still runs faster than my full install.

What's going on? How do I fix this?

The issue is the Unity settings in CCSM. The "Dash Blur" setting was set to "Static Blur". Changing that back to "No Blur" fixes the issue. I suppose this is why it's under the "Experimental" tab.

By the way, the list of PCI devices was the same and I did not try disabling OpenGL because I don't want to disable all the plugins that use it.