Sharing some more information on this matter;
I’ve installed a plugin called Core Control to see exactly what cron jobs are being executed.
This is what I get;
Once Off | 2013-01-22 / 23:46:42 -0 | ns_doPublishToTW | Hooked functions: nxs_doPublishToTW() | 1782, Array | Cancel Task | Run Now
I get two for the same post id, one for TW(itter) and one for FB(facebook).
The option is ticked for the user groups in question, If I select publish immdiatley this also works, but I would rather it be delayed?
My theme has custom post types, so instead of posting standard posts, it posts videos.
Theme is deTube, https://demo.dedepress.com/detube/#