Safari 8.0 web process at 100% CPU every time I start Safari after resuming from sleep [closed]

Whenever I start Safari 8.0 (on Yosemite 10.10) after resuming my Mac from sleep, it kicks off a web process which consumes 100% CPU and soon gets the fans on my MBA going:

What's strange is that it's always the same URL (http://www.saudecuf.pt/) which is a site I haven't visited for a very long time, certainly not since I upgraded to 10.10. I have no idea why it's picking up that URL. The only solution is to force quit that process and from then on Safari behaves normally until the next time I put my Mac to sleep.

Very frustrating.

BTW: the site is the site of a local private hospital, nothing special.

Sorry it's not a solution, but just to reassure you that you're not going mad: I have the exact same problem, different URL, but similarly old and unvisited - it's not even an open tab or within top-sites.

However, as well as peaking at 98% CPU usage, I also eventually get the red error notice in Activity Monitor 'Safari Web content (not responding)' and everything slows down - although Safari is mostly still usable.

I've tried disabling extensions and iCloud sync. Even restarting doesn't remove the old URL.