After reviewing Tom’s thread-link I read a bit longer into the solutions and links to the Microsoft blogs and discovered that the solution was almost spot-on but missed the correct CSS definition. To be complete and working with Windows Phone 8 it should be:
.flexslider {
touch-action: pan-y !important;
-ms-touch-action: pan-y !important;
}
This code is tested and compatible with platform/browsers of type WinPhone8/IEMobile.