The link for Url manager has been moved. You should see a link for Advanced Tools, click that and you'll see the link for Url Manager. Url Manager has been moved their becuase most people should never have to mess with Url Manager.
If your WebStore installation is having errors, it may redirect you to home. Look in the system log for errors that might give a clue about the problem.
Maybe clear the log first then cause the error to make it easier to find it in the log.
Hope it helps,
Joe