For the past couple of days when I watch videos on YouTube on my iMac it's VERY slow to start. Sometimes it takes minutes, at which point I have to refresh, and best case it takes about 1 minute to start. I have cleared the startup cache, cleared cookies and restarted Firefox. Also, YouTube works normally on both Safari and Chrome. Not a super 'tech' guy so any basic steps I can take are appreciated. Thank you! D