Newsblur forgets which feeds are read and which ones aren’t when changing computers or even just using a different browser.
The main reason I use an online feed reader is so that when I have to change computers, that which feeds I’ve read are remembered.
Yeah, NewsBlur synchronizes between multiple computers. In fact, you can have NewsBlur open all day on multiple computers and they will stay in sync. I’m tempted to think this is a cookie issue. Can you clear your *.newsblur.com cookies and see if the issue persists?