Preload stuck. Cache unusable

WP-Super Cache seems to be stuck. I cancelled a preload and now it became unusable. Nothing is being cached and according to the preload screen, it will take up to 1 minute for the caching to finish…. that’s now an hour ago. I need to preload my page. How to “reset” this situation. Uninstalling and re-installing does not change much.

Thanks in advance.

The page I need help with: [log in to see the link]