I also have this same problem with the Evernote web clipper and it is driving me insane. It doesn't happen every time but it does happen most of the time. I've also noticed that for me it crashes whatever tab I was trying to clip from and the tab immediately to the left.

I often right click a link in facebook and 'open in new tab' and then try to clip something from the new tab. The new tab crashes as well as my facebook tab. This is just an example though and it doesn't have to be a new tab from just a facebook tab.

As a workaround, it seems I can right click the tab I want to clip and select 'clone tab' and clip from the the cloned tab without a problem.

I've had this problem for a looooong time now through many iterations of both Opera and the Evernote Web Clipper and on various different computers. I've also tested with no other extensions other than the Evernote Web Clipper enabled and I still get the problem. Sometimes I think it's gone away but it eventually rears its ugly head again. And once it starts happening, it happens almost every time I try to clip a page.

I have this problem on both Windows 7, Windows 8.1, and (I believe) my iMac running Snow Leopard.