This is the way that the User Registration Solution Pack is designed to work, if the user attempts to access a page that is restricted they will be redirected to the login page. Once they login it should return them to the page that they were restricted from viewing. What controls this is the gotoPreviousURL setting in the authenticate user server behavior on the login page:
"gotoPreviousURL" => TRUE,
If your setting is not set to true like above you should change it to be true.