Published project stops loading mid-slide at client end

I'm trying to get a small information resource for a client to work properly. Prior to this project I asked the client to test a small storyline 'web' published project, including an embedded video. They reported that it worked perfectly at their end.

I have just published the project in the same way, copying files to the same server. It is not appreciably larger than the demo I did. It contains nothing special, standard storyline stuff. But the client reports that the loading of it stopped half-way through the second slide, the main menu, and stuck there, despite several tries.

To my mind, if there is a security issue, the thing should either load, or fail, or perhaps certain things might not work, such as hyperlinks, etc - no such issue here - or am I being too naive?

I'd appreciate any feedback as to whether it loads OK:

www.moleculestomarkets.com/M2M_online/story.html

Plus, any insight into what might cause this specific problem?