On both Mac Safari v6.1.6 and 7.1, I can't get video thumbs from YouTube to display. They show up fine on Firefox and Chrome.

Examples include:
Bissell Maple Farm
and
Total Customized Fitness

Any thoughts? I've tried dumping the cache and reseting Safari, but the issue persists.

I bet you've got an active debugger or developer tool running that's breaking things.

I no longer have access to a Mac for testing, but Safari on Windows will show the YouTube thumbs just fine - unless I have Firebug Light activated.

Can you please get any debug and developer consoles out of the way and see what your experience is then.

Thanks--that was it. Turning off showing the Develop menu in preferences made the thumbs visible.

Appreciate the prompt response.