Visible when scroll up

Hi, i ve bought your plugin to have the possibility to see the menu when i scroll up. Not possible. So i ve changed css like that to fix my menu on top when i scroll up, it s working but mask top of page when up.

#mysticky-nav.up {
position: fixed;
left: 0px;
top : 0 !important
}

Could you fix it ?
Thanks.
Lionel