Defenders of Ardania Collection 75% today only

I saw it and snatched up the deal, having missed the "Warlock Of The Arcane" sale. My problem is it has activated on Steam but will not download (and yes, everything is working just fine including the internet). Other items are downloading and completing but this has stalled at 1%.
Very strange and Steam ticket submitted, though I hate dealing with Steam Support. They never offer any useful advice and eventually fob you off with a shrug - "It's not our fault, it's yours".

EDIT: Got to 4% this time (after uninstalling and re-installing for the umpteenth time), and now yet again it has suspended. *groan*