Problem with dropped connection

Our website is https://talesofahalfcentury.net. My co-administrator keeps having a problem that I don’t seem able to help with, since I can’t seem to reproduce it on my machine. I’m running a PC using Windows 7 and Firefox; he’s using a Mac with Safari. It seems that when he’s been doing work in the Dashboard and then seeks to return to the site, he loses the connection – his machine freezes up, and he essentially has to reboot his connection. Does anyone have any ideas as to why this might be occurring?

He has had the same problem using Firefox as well. At least he no longer insists it’s a fundamental flaw in the system, or in WordPress itself.

If there’s any more info that you might need to assess what’s going on let me know and I’ll see if I can get it out of him.

Thanks!