OK, you need to reboot the box after having made any changes in the WebIf Channel Editor (wait for the page to finish handling changes and then also wait for the page to fully render again first, before rebooting) - before pushing the channels.I rebooted the box - waited half an hour - used the Webif Channel Editor - then pushed the channels - I think!
Perhaps worth rebooting the box at this point, then go back into WebIf Channel Editor and check that your changes are there, and then try to push the channels again.
I've asked af123 to check whether he can find any clues regarding this on the RS Portal.