Hi Simon,
This behavior is by design but you can set mojoPortal to display the menus on the login, register, password recovery and other pages by settings options in your user.config.
<add key="HideMenusOnLoginPage" value="true" />
<add key="HideMenusOnRegisterPage" value="true" />
<add key="HideMenusOnPasswordRecoveryPage" value="true" />
<add key="HideMenusOnChangePasswordPage" value="true" />
<add key="HideAllMenusOnProfilePage" value="false" />
<add key="HidePageMenuOnProfilePage" value="true" />
<add key="HideAllMenusOnMyPage" value="false" />
<add key="HideMenusOnSiteMap" value="true" />
<add key="HidePageMenusOnSiteMap" value="true" />
The options above are shown with their defaults. You only need to copy the options you plan to change to your user.config. After copying them to your user.config, you must open the web.config and save it to recycle the application.
Hope this helps,
Joe D.