Both the Survey and the Poll features were contributed long ago by a community member. The work flow of those features is a bit convoluted compared to other features.
With the survey feature you have to create a survey, create pages, put questions on the pages, activate the survey etc, you'll figure it out if you bang around on it long enough.
However if you want something easier to use and more flexible consider our add on product Form Wizard Pro.
Note that since the add on products fund development of mojoPortal we don't ever plan to improve the free Survey feature since it competes with Form Wizard Pro.
Hope that helps,