Hello, I don't have problems to trust diigo. But the workaround 1+2 works only if I allow mixed content for all web-sites (not only for the trusted www.diigo.com).
The alternative method choosing "don't show annotations" would be fine for me, but it does not work. I choose it: (Screenshot http://www.diigo.com/item/image/13zzp/kvxi ) but I still get warnings from internet-explorer when I open a website with https.