Is it maybe somehow disabled in your registry?
Go to Run in teh Start menu and type in regedit
Then expand HKEY_CURRENT_USER if it isn't already
Then go to Control Panel\Desktop And click on desktop and then click on coolswitch.
Its values should be 1 if it is enabled and it will be 0 if it is disabled. If it is 0 right click on it and go to modify and put in a 1.
You can also change the default of 7 items across the column if you want.
Hope that helps.