C-Net little icon thingy problem in Firefox

I wonder if anyone else is having this problem.

I make frequent use of the "Bookmarks" toolbar in Firefox (I'm using version 1.5.0.3), where you can drag the most-used website links so they're right there when you need them. (Little tip: you can change the text associated with each link so it's shorter, and fit more links that way. This works in IE as well. For instance, my link to the Buzz Out Loud Lounge is labelled BOLL. On my laptop I have 19 links showing on the toolbar -- there are more on my desktop computer now that I have a larger monitor.)

Each of these items has a little picture with it. I know there's a more specific name for these little things than icon, but it escapes me now what it is. Some (most) of my links have their own unique, logo-type icon. The ones that don't, have a little white page with a folded corner, must be the default icon Firefox uses for those who haven't created their own.

Here's my problem: I have 2 C-Net links on there, and they have no picture at all. There's a spot for one, but it's blank, there's no logo, no picture.

My questions: First, do others experience this phenomenon? Second, anyone know why it happens or if there's a way to fix it?