We are facing this problem since we upgraded to 1.9.4.
Since we upgrade, Youtube videos loading slow .. I thought something in our upgrade wrong.
I did format and installed (Fedora 12 + squid + apache + videocache) and every thing is working fine accept Youtube.
When watching new video .. its downloaded and cached.
When watching it again .. in logs saying its served from cache but looking at my main router i see its downloading again .. iam not taking it from cache.
More i did test on redtube .. its working very good .. when watching cached video ... iam taking it with high speed.
So cached Youtube videos (only) not surfing from cache though in logs writing served from cache .. That is why its slow while loading streaming video .. its taking it back directly from internet.
Any help !!