No thanks, I resolved the problem myself while waiting for a reply.
Funnily enough, if I accessed the Steam Store page from my browser Opera, rather than through Steam, it worked.
That pack is an awesome deal, assuming you'd actually play the games and don't own most of them already.
CoH I've already played, DoW never did much for me... Not worth buying for me. Buy it if you think you'll actually get fair use out of all the games, don't just buy it because it's a good deal.