You can't use the keyboard to navigate to the Up One Level, Home, Create New Folder, List, and Details buttons.

These buttons need to be activatable using the Spacebar and Enter keys.

The tool tip for each button should pop up or support being called up using the following keysequences (see bug #s 4108466, 4108467, 4110485):
Post tip - Ctrl+F1 (for component with focus)
Unpost tip - Esc and Ctrl+F1