I've seen a similar effect here as well from time to time.

 I always attributed it to a server timing out. I'm on slower dial up so I will open 10 to 15 threads in new windows and let them be loading while I start reading the first ones I clicked on. On a rare occasion when I get to the last few that I had opened they will have an appearance like those in the screen shot with some of the text showing but the dreaded little boxes with the red X.

 A refresh of the page always restores it to how it should be.